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

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
			}
		}
	}
}

var selectedtitle=getCookie("mysheet")
if (document.getElementById && selectedtitle != null) { //load user chosen style sheet from cookie if there is one stored
	setStylesheet(selectedtitle)
}