//Style Sheet Switcher version 1.1 Oct 10th, 2006
//Author: Dynamic Drive: http://www.dynamicdrive.com
//Usage terms: http://www.dynamicdrive.com/notice.htm

var manual_or_random="manual" //"manual" or "random"
var randomsetting="3 days" //"eachtime", "sessiononly", or "x days (replace x with desired integer)". Only applicable if mode is random.

//////No need to edit beyond here//////////////

function getCookie(Name) { 
var re=new RegExp(Name+"=[^;]+", "i"); //construct RE to search for target name/value pair
if (document.cookie.match(re)) //if cookie found
return document.cookie.match(re)[0].split("=")[1] //return its value
return null
}

function setCookie(name, value, days) {
var expireDate = new Date()
//set "expstring" to either future or past date, to set or delete cookie, respectively
var expstring=(typeof days!="undefined")? expireDate.setDate(expireDate.getDate()+parseInt(days)) : expireDate.setDate(expireDate.getDate()-5)
document.cookie = name+"="+value+"; expires="+expireDate.toGMTString()+"; path=/";
}

function deleteCookie(name){
setCookie(name, "moot")
}


function setStylesheet(title, randomize){ //Main stylesheet switcher function. Second parameter if defined causes a random alternate stylesheet (including none) to be enabled
var i, cacheobj, altsheets=[""]
for(i=0; (cacheobj=document.getElementsByTagName("link")[i]); i++) {
if(cacheobj.getAttribute("rel").toLowerCase()=="alternate stylesheet" && cacheobj.getAttribute("title")) { //if this is an alternate stylesheet with title
cacheobj.disabled = true
altsheets.push(cacheobj) //store reference to alt stylesheets inside array
if(cacheobj.getAttribute("title") == title) //enable alternate stylesheet with title that matches parameter
cacheobj.disabled = false //enable chosen style sheet
}
}
if (typeof randomize!="undefined"){ //if second paramter is defined, randomly enable an alt style sheet (includes non)
var randomnumber=Math.floor(Math.random()*altsheets.length)
altsheets[randomnumber].disabled=false
}
return (typeof randomize!="undefined" && altsheets[randomnumber]!="")? altsheets[randomnumber].getAttribute("title") : "" //if in "random" mode, return "title" of randomly enabled alt stylesheet
}

function chooseStyle(styletitle, days){ //Interface function to switch style sheets plus save "title" attr of selected stylesheet to cookie
if (document.getElementById){
setStylesheet(styletitle)
setCookie("mysheet", styletitle, days)
}
}

function indicateSelected(element){ //Optional function that shows which style sheet is currently selected within group of radio buttons or select menu
if (selectedtitle!=null && (element.type==undefined || element.type=="select-one")){ //if element is a radio button or select menu
var element=(element.type=="select-one") ? element.options : element
for (var i=0; i<element.length; i++){
if (element[i].value==selectedtitle){ //if match found between form element value and cookie value
if (element[i].tagName=="OPTION") //if this is a select menu
element[i].selected=true
else //else if it's a radio button
element[i].checked=true
break
}
}
}
}

if (manual_or_random=="manual"){ //IF MANUAL MODE
var selectedtitle=getCookie("mysheet")
if (document.getElementById && selectedtitle!=null) //load user chosen style sheet from cookie if there is one stored
setStylesheet(selectedtitle)
}
else if (manual_or_random=="random"){ //IF AUTO RANDOM MODE
if (randomsetting=="eachtime")
setStylesheet("", "random")
else if (randomsetting=="sessiononly"){ //if "sessiononly" setting
if (getCookie("mysheet_s")==null) //if "mysheet_s" session cookie is empty
document.cookie="mysheet_s="+setStylesheet("", "random")+"; path=/" //activate random alt stylesheet while remembering its "title" value
else
setStylesheet(getCookie("mysheet_s")) //just activate random alt stylesheet stored in cookie
}
else if (randomsetting.search(/^[1-9]+ days/i)!=-1){ //if "x days" setting
if (getCookie("mysheet_r")==null || parseInt(getCookie("mysheet_r_days"))!=parseInt(randomsetting)){ //if "mysheet_r" cookie is empty or admin has changed number of days to persist in "x days" variable
setCookie("mysheet_r", setStylesheet("", "random"), parseInt(randomsetting)) //activate random alt stylesheet while remembering its "title" value
setCookie("mysheet_r_days", randomsetting, parseInt(randomsetting)) //Also remember the number of days to persist per the "x days" variable
}
else
setStylesheet(getCookie("mysheet_r")) //just activate random alt stylesheet stored in cookie
} 
}


// rotating image change for homepage
function changeQuote()
{
var quotes = new Array(
'<p>&quot;OpenCourseWare is exactly the kind of thing that universities should be doing.&quot;</p><ul><li><strong>Larry Birenbaum</strong><br />MIT Class of 1969 and OCW supporter<br /> United States</li></ul>', 
'<p>&quot;Through OCW, I am part of a movement to help make education free and available to the world.&quot;</p><p><ul><li><strong>Clinton Blackburn</strong><br />MIT student<br />United States</li></ul>', 
'<p>&quot;I was amazed that a university such as MIT would freely give access to its educational information.&quot;</p><ul><li><b>Triatno Yudo Harjoko</b><br />Educator<br />Indonesia</li></ul>',
'<p>&quot;When I realized I could follow along with an MIT course... I thought, \'I can handle this!\'&quot;</p><ul><li><b>Ali Sheikh</b><br />Student<br />United States</li></ul>', 
'<p>&quot;OCW is definitely going to help me make decisions about what to study in the future.&quot;</p><ul><li><b>Benjamin Goff</b><br />Self learner<br />United States</li></ul>', 
'<p>&quot;I found lecture notes, handouts and slides from presentations, and some problem sets. It helped me a lot.&quot;</p><ul><li><b>Maria Karamitsou</b><br />Student<br />Greece</li></ul>',
'<p>&quot;OCW opens up knowledge across the world and allows universities to benchmark teaching.&quot;</p><ul><li><b>François Viruly</b><br />Educator<br />South Africa</li></ul>',
'<p>&quot;My life is in teaching. To have a chance to do that with a world audience is just wonderful.&quot;</p><ul><li><b>Gilbert Strang</b><br />MIT Mathematics professor<br />United States</li></ul>',
'<p>&quot;It\'s a great opportunity for students to become extraordinary engineers.&quot;</p><ul><li><b>Juan Lara</b><br />Student<br />Mexico</li></ul>',
'<p>&quot;It puts a previously untouchable subject within reach for anyone who is interested.&quot;</p><ul><li><b>Wendy Ermold</b><br />Self Learner<br />United States</li></ul>',
'<p>&quot;I strive to make as much as possible enjoyable and educational at the same time.&quot;</p><ul><li><b>Amy Santee</b><br />Educator<br />United States</li></ul>',
'<p>&quot;It\'s an important way to ensure the quality of my courses.&quot;</p><ul><li><b>Shirley Harrell</b><br />Educator<br />United States</li></ul>',
'<p>&quot;OCW will enable us to create better educational linkages.&quot;</p><ul><li><b>Karen Willcox</b><br />MIT Aeronautics and Astronautics professor<br />United States</li></ul>');

var images = new Array (
"/OcwWeb/images/wihomeimages/birenbaum.jpg", 
"/OcwWeb/images/wihomeimages/blackburn.jpg", 
"/OcwWeb/images/wihomeimages/harjoko.jpg",
"/OcwWeb/images/wihomeimages/sheikh.jpg",
"/OcwWeb/images/wihomeimages/goff.jpg",
"/OcwWeb/images/wihomeimages/karamitsou.jpg",
"/OcwWeb/images/wihomeimages/viruly.jpg",
"/OcwWeb/images/wihomeimages/gil3.jpg",
"/OcwWeb/images/wihomeimages/juan_banner.jpg",
"/OcwWeb/images/wihomeimages/wendy_banner.jpg",
"/OcwWeb/images/wihomeimages/santee_banner.jpg",
"/OcwWeb/images/wihomeimages/harrell_banner.jpg",
"/OcwWeb/images/wihomeimages/willcox_banner.jpg");

var links = new Array (
"/OcwWeb/web/about/stories/birenbaum/birenbaum.htm", 
"/OcwWeb/web/about/stories/blackburn/blackburn.htm", 
"/OcwWeb/web/about/stories/harjoko/harjoko.htm",
"/OcwWeb/web/about/stories/sheikh/sheikh.htm",
"/OcwWeb/web/about/stories/goff/goff.htm",
"/OcwWeb/web/about/stories/karamitsou/karamitsou.htm",
"/OcwWeb/web/about/stories/viruly/viruly.htm",
"/OcwWeb/web/about/stories/strang/strang.htm",
"/OcwWeb/web/about/stories/lara/lara.htm",
"/OcwWeb/web/about/stories/ermold/ermold.htm",
"/OcwWeb/web/about/stories/santee/santee.htm",
"/OcwWeb/web/about/stories/harrell/harrell.htm",
"/OcwWeb/web/about/stories/willcox/willcox.htm");

var rand = Math.floor(Math.random()*quotes.length);
var txt='';
txt+='<ul><li class="email"><a href="javascript:emailPopUp()">Email this page<\/a><\/li><\/ul>';
if(document.getElementById("switchbutton"))
	document.getElementById("switchbutton").innerHTML=txt;
document.getElementById("EWebEditProPlaceholder1").style.backgroundImage = "url("+images[rand]+")";
var mainQuotesPlaceHolder = document.getElementById("quote_main");
if(mainQuotesPlaceHolder){
	mainQuotesPlaceHolder.innerHTML = quotes[rand] + '<p><a href="' + links[rand] + '"  class="bullet">Read more<\/a><\/p>';
	}

}


// rotating image change ends here

window.onload=function(){
var txt='';
txt+='<ul><li class="email"><a href="javascript:emailPopUp()">Email this page<\/a><\/li><\/ul><div class="clear"><\/div>';
if(document.getElementById("switchbutton"))
	document.getElementById("switchbutton").innerHTML=txt;
showRandomSidebarQuote();
populateAPPagesRSI();
populateYoutubePlaceholders();
showRandomIndividualSupporterQuote();
}

function showRandomSidebarQuote()
{
	var quotes = new Array(
	'<p>&quot;I donated because I want MIT to keep OCW going.&quot;<br /><br /> &mdash;Heath Novak<br />Student, USA</p>', 
	'<p>&quot;OCW inspires just as much as it enriches.&quot;<br /><br /> &mdash;Jeff Breidenbach<br /> MIT Alumnus, Class of 1996</p>',
	'<p>&quot;It\'s every person\'s responsibility to stand up and support the things he (or she) values.&quot;<br /><br /> &mdash;Assaf Tal<br /> Self Learner, Israel</p>',
	'<p>&quot;Supporting OCW was my way of saying \'thank you\' for having the courage and insight to take this bold step.&quot;<br /><br /> &mdash;Ted Inoue<br /> Self Learner, USA</p>',
	'<p>&quot;I gained so much by the educational materials from MIT faculty.&quot;<br /><br /> &mdash;Aditi Gupta<br /> Student, USA</p>',
	'<p>&quot;OCW has been instrumental in my professional development.&quot;<br /><br /> &mdash;Harry Crissy<br /> Self Learner, USA</p>') 
	
	var rand = Math.floor(Math.random() * quotes.length);
	var sidebarQuotesPlaceHolder = document.getElementById("quote_sidebar");
	if(sidebarQuotesPlaceHolder){
		sidebarQuotesPlaceHolder.innerHTML = quotes[rand];
	}
}
function showRandomIndividualSupporterQuote()
{
	var images = new Array (
	"/OcwWeb/images/individualsupporter/donor_1.gif", 
	"/OcwWeb/images/individualsupporter/donor_2.gif", 
	"/OcwWeb/images/individualsupporter/donor_3.gif",
	"/OcwWeb/images/individualsupporter/donor_4.gif",
	"/OcwWeb/images/individualsupporter/donor_5.gif",
	"/OcwWeb/images/individualsupporter/donor_6.gif",
	"/OcwWeb/images/individualsupporter/donor_7.gif",
	"/OcwWeb/images/individualsupporter/donor_8.gif",
	"/OcwWeb/images/individualsupporter/donor_9.gif",
	"/OcwWeb/images/individualsupporter/donor_10.gif");

	var quotes = new Array(
	'OpenCourseWare is how MIT will be remembered 500 years from now.',
	'I gave to OCW because I think it\'s one of the most noble endeavors imaginable. MIT, you rock! I\'m so proud of you!',
	'I\'ve used OCW as a reference long after my old college \'bibles\' ended up in the recycling bin. OCW is a shining example of ideas being celebrated.',
	'I\'ve been dreaming for years an initiative like the OCW for young students in Haiti and other Developing countries.',
	'I know the value of good educational content - and the tangible positive changes it can bring to an aspiring student. It really transforms life.',
	'I support you because you support me! Thank you for contributing to my professional development.',
	'As a Physics teacher, I find your website to be of enormous utility both for my own edification, as well as the education of my students.',
	'I find it inspiring that so many people, rich or poor, get to learn anything they desire from OpenCourseWare.',
	'This is the way education should be: open, high-quality and available to all who are interested in learning.',
	'This is what education is all about and it is boundless. This is why I support OCW.') 
	
	var rand = Math.floor(Math.random() * quotes.length);
	var sidebarQuotesPlaceHolder = document.getElementById("rotating_quotes");
	if(sidebarQuotesPlaceHolder){
		sidebarQuotesPlaceHolder.innerHTML = '<p><img title="' + quotes[rand] + '" src="' + images[rand] + '" alt="' + quotes[rand] + '" \/><\/p>';
	}
}

function emailPopUp()
{
	var pageTitle = document.title;
	var pageUrl   = document.location;
	var URL = "/OcwWeb/jsp/emailpage.jsp?title=" + pageTitle + "&referer=" + pageUrl;
	window.open(URL,null,"height=470,width=530,status=yes,toolbar=no,menubar=no,location=no,resizable=yes");
}
function clearSearchBox()
{
	if(document.getElementById("terms").value == "Enter search keyword")
	{
		document.getElementById("terms").value = "";	
	}
	
}
function clearEmailBox()
{

	if(document.getElementById("txt_subscribe").value == "Enter email address")
	{
		document.getElementById("txt_subscribe").value = "";	
	}
	
}

function fillSearchBox()
{
	if(document.getElementById("terms").value == "")
	{
		document.getElementById("terms").value = "Enter search keyword";	
	}
}
function fillEmailBox()
{
	if(document.getElementById("txt_subscribe").value == "")
	{
		document.getElementById("txt_subscribe").value = "Enter email address";	
	}
}
function SearchOptionChanged()
{
	if (document.getElementById("searchSelection").selectedIndex!='0' && document.getElementById("searchSelection").selectedIndex!='1')
	{
		document.getElementById("searchInOcwSite").disabled = true;
		document.getElementById("siteSelectionIndex").value = document.getElementById("searchSelection").selectedIndex;
	}

	if (document.getElementById("searchSelection").selectedIndex=='1')
	{
		document.getElementById("searchInOcwSite").disabled = false;
		document.getElementById("searchInOcwSite").value = 'ocw';
		document.getElementById("siteSelectionIndex").value = document.getElementById("searchSelection").selectedIndex;
	}
	else
	if(document.getElementById("searchSelection").selectedIndex=='0')
	{
		document.getElementById("searchInOcwSite").disabled = false;
		document.getElementById("searchInOcwSite").value = 'ocwhs';
		document.getElementById("siteSelectionIndex").value = document.getElementById("searchSelection").selectedIndex;
	}

}
function setSiteSelection()
{
	// fetch the value of siteSelectionIndex from URL
	var selectionIndex=getParameter ("siteSelectionIndex");	
  	document.getElementById("searchSelection").selectedIndex = selectionIndex;
  	SearchOptionChanged();	
}

function getParameter (parameterName ) {
// Add "=" to the parameter name (i.e. parameterName=value)
var queryString = window.top.location.search.substring(1);

var parameterName = parameterName + "=";
if ( queryString.length > 0 ) {
// Find the beginning of the string
begin = queryString.indexOf ( parameterName );
// If the parameter name is not found, skip it, otherwise return the value
if ( begin != -1 ) {
// Add the length (integer) to the beginning
begin += parameterName.length;
// Multiple parameters are separated by the "&" sign
end = queryString.indexOf ( "&" , begin );
if ( end == -1 ) {
end = queryString.length
}
// Return the string
return unescape ( queryString.substring ( begin, end ) );
}
// Return "null" if no parameter has been found
return "null";
}
} 
function populateAPPagesRSI()
{
	var APPhysicsReferenceList = document.getElementById("APPhysicsRSI");
	var APCalculusReferenceList = document.getElementById("APCalculusRSI");
	var APBiologyReferenceList = document.getElementById("APBiologyRSI");

	if(APPhysicsReferenceList)
	{
		APPhysicsReferenceList.innerHTML = renderAPRSIHTML(APPhysicsCourseReferencesText,APPhysicsCourseReferencesLink);
	}
	if(APCalculusReferenceList)
	{
		APCalculusReferenceList.innerHTML = renderAPRSIHTML(APCalculusCourseReferencesText,APCalculusCourseReferencesLink);
	}
	if(APBiologyReferenceList)
	{
		APBiologyReferenceList.innerHTML = renderAPRSIHTML(APBiologyCourseReferencesText,APBiologyCourseReferencesLink);
	}
	
}
function renderAPRSIHTML(referenceNames,referenceLinks)
{
	var APRSIReferenceHTML = '';
	for(var referenceIndex = 0; referenceIndex < referenceLinks.length; referenceIndex++)
		{
			APRSIReferenceHTML += '<p class="course_ref bullet"><a title="Launch a new window to view this page." href=';
			APRSIReferenceHTML += referenceLinks[referenceIndex];
			APRSIReferenceHTML += ' target="_blank">';
			APRSIReferenceHTML += referenceNames[referenceIndex];
			APRSIReferenceHTML += '</a><img src="/OcwWeb/images/new_window.gif" /></p>'
		}
	return APRSIReferenceHTML;
}

// Start code for injecting tags for embedding YouTube videos
document.getElementsByClassName = function(cl) {
        var retnode = [];
        var myclass = new RegExp('\\b'+cl+'\\b');
        var elem = this.getElementsByTagName('*');
        for (var i = 0; i < elem.length; i++) {
                var classes = elem[i].className;
                if (myclass.test(classes)) retnode.push(elem[i]);
        }
        return retnode;
};

function populateYoutubePlaceholders(){
	
	if(CanCurrentTemplateExecuteYouTubeScript())
        {
		var stringToReplace = "ACTUAL_LINK_GOES_HERE";
		var videoinjectionstring = '<object type="application/x-shockwave-flash" style="width:425px; height:344px;" data="' + stringToReplace+ '">'
                + '<param name="movie" value="' + stringToReplace + '"></param>'
                + '<param name="allowFullScreen" value="true"></param></object>';
        var videoContainers = document.getElementsByClassName("youtubevideo");
		for(i = 0; i < videoContainers.length; i ++){
			var videoURL = videoContainers[i].getElementsByTagName("a")[0].getAttribute("href");
			var finalvideoinjectionstring = videoinjectionstring.replace(stringToReplace, videoURL).replace(stringToReplace, videoURL);
			videoContainers[i].innerHTML = finalvideoinjectionstring;
		}
        }
}

function CanCurrentTemplateExecuteYouTubeScript(){
	
	var templatesToDisable = new Array (
		"SiteHomePage.aspx", 
		"DepartmentHomePage.aspx", 
		"MasterCourseList.aspx",
		"ArchiveCourseList.aspx",
		"AFcourseList.aspx",
		"CourseList.aspx");
		
	//For all CMS pages (ONLY) __CMS_CurrentUrl contains the template name - this variable does not exist in orphaned pages
	if (typeof(__CMS_CurrentUrl) == "undefined")
	{
		return false;
	}
	else
	{
		for (templateCounter = 0; templateCounter < templatesToDisable.length; templateCounter++)
		{
			if (__CMS_CurrentUrl.match(templatesToDisable[templateCounter]) != null)
			{
				return false;
			}
		}
		//for all other templates and pages return true
		return true;
	}
}
// End code for injecting tags for embedding YouTube videos