function ddtabcontent(tabinterfaceid){

	this.tabinterfaceid=tabinterfaceid //ID of Tab Menu main container

	this.tabs=document.getElementById(tabinterfaceid).getElementsByTagName("a") //Get all tab links within container

	this.enabletabpersistence=true

	this.hottabspositions=[] //Array to store position of tabs that have a "rel" attr defined, relative to all tab links, within container

	this.currentTabIndex=0 //Index of currently selected hot tab (tab with sub content) within hottabspositions[] array

	this.subcontentids=[] //Array to store ids of the sub contents ("rel" attr values)

	this.revcontentids=[] //Array to store ids of arbitrary contents to expand/contact as well ("rev" attr values)

	this.selectedClassTarget="link" //keyword to indicate which target element to assign "selected" CSS class ("linkparent" or "link")

}



ddtabcontent.getCookie=function(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 ""

}



ddtabcontent.setCookie=function(name, value){

	document.cookie = name+"="+value+";path=/" //cookie value is domain wide (path=/)

}



ddtabcontent.prototype={



	expandit:function(tabid_or_position){ //PUBLIC function to select a tab either by its ID or position(int) within its peers

		this.cancelautorun() //stop auto cycling of tabs (if running)

		var tabref=""

		try{

			if (typeof tabid_or_position=="string" && document.getElementById(tabid_or_position).getAttribute("rel")) //if specified tab contains "rel" attr

				tabref=document.getElementById(tabid_or_position)

			else if (parseInt(tabid_or_position)!=NaN && this.tabs[tabid_or_position].getAttribute("rel")) //if specified tab contains "rel" attr

				tabref=this.tabs[tabid_or_position]

		}

		catch(err){alert("Invalid Tab ID or position entered!")}

		if (tabref!="") //if a valid tab is found based on function parameter

			this.expandtab(tabref) //expand this tab

	},



	cycleit:function(dir, autorun){ //PUBLIC function to move foward or backwards through each hot tab (tabinstance.cycleit('foward/back') )

		if (dir=="next"){

			var currentTabIndex=(this.currentTabIndex<this.hottabspositions.length-1)? this.currentTabIndex+1 : 0

		}

		else if (dir=="prev"){

			var currentTabIndex=(this.currentTabIndex>0)? this.currentTabIndex-1 : this.hottabspositions.length-1

		}

		if (typeof autorun=="undefined") //if cycleit() is being called by user, versus autorun() function

			this.cancelautorun() //stop auto cycling of tabs (if running)

		this.expandtab(this.tabs[this.hottabspositions[currentTabIndex]])

	},



	setpersist:function(bool){ //PUBLIC function to toggle persistence feature

			this.enabletabpersistence=bool

	},



	setselectedClassTarget:function(objstr){ //PUBLIC function to set which target element to assign "selected" CSS class ("linkparent" or "link")

		this.selectedClassTarget=objstr || "link"

	},



	getselectedClassTarget:function(tabref){ //Returns target element to assign "selected" CSS class to

		return (this.selectedClassTarget==("linkparent".toLowerCase()))? tabref.parentNode : tabref

	},



	urlparamselect:function(tabinterfaceid){

		var result=window.location.search.match(new RegExp(tabinterfaceid+"=(\\d+)", "i")) //check for "?tabinterfaceid=2" in URL

		return (result==null)? null : parseInt(RegExp.$1) //returns null or index, where index (int) is the selected tab's index

	},



	expandtab:function(tabref){

		var subcontentid=tabref.getAttribute("rel") //Get id of subcontent to expand

		//Get "rev" attr as a string of IDs in the format ",john,george,trey,etc," to easily search through

		var associatedrevids=(tabref.getAttribute("rev"))? ","+tabref.getAttribute("rev").replace(/\s+/, "")+"," : ""

		this.expandsubcontent(subcontentid)

		this.expandrevcontent(associatedrevids)

		for (var i=0; i<this.tabs.length; i++){ //Loop through all tabs, and assign only the selected tab the CSS class "selected"

			this.getselectedClassTarget(this.tabs[i]).className=(this.tabs[i].getAttribute("rel")==subcontentid)? "selected" : ""

		}

		if (this.enabletabpersistence) //if persistence enabled, save selected tab position(int) relative to its peers

			ddtabcontent.setCookie(this.tabinterfaceid, tabref.tabposition)

		this.setcurrenttabindex(tabref.tabposition) //remember position of selected tab within hottabspositions[] array

	},



	expandsubcontent:function(subcontentid){

		for (var i=0; i<this.subcontentids.length; i++){

			var subcontent=document.getElementById(this.subcontentids[i]) //cache current subcontent obj (in for loop)

			subcontent.style.display=(subcontent.id==subcontentid)? "block" : "none" //"show" or hide sub content based on matching id attr value

		}

	},



	expandrevcontent:function(associatedrevids){

		var allrevids=this.revcontentids

		for (var i=0; i<allrevids.length; i++){ //Loop through rev attributes for all tabs in this tab interface

			//if any values stored within associatedrevids matches one within allrevids, expand that DIV, otherwise, contract it

			document.getElementById(allrevids[i]).style.display=(associatedrevids.indexOf(","+allrevids[i]+",")!=-1)? "block" : "none"

		}

	},



	setcurrenttabindex:function(tabposition){ //store current position of tab (within hottabspositions[] array)

		for (var i=0; i<this.hottabspositions.length; i++){

			if (tabposition==this.hottabspositions[i]){

				this.currentTabIndex=i

				break

			}

		}

	},



	autorun:function(){ //function to auto cycle through and select tabs based on a set interval

		this.cycleit('next', true)

	},



	cancelautorun:function(){

		if (typeof this.autoruntimer!="undefined")

			clearInterval(this.autoruntimer)

	},



	init:function(automodeperiod){

		var persistedtab=ddtabcontent.getCookie(this.tabinterfaceid) //get position of persisted tab (applicable if persistence is enabled)

		var selectedtab=-1 //Currently selected tab index (-1 meaning none)

		var selectedtabfromurl=this.urlparamselect(this.tabinterfaceid) //returns null or index from: tabcontent.htm?tabinterfaceid=index

		this.automodeperiod=automodeperiod || 0

		for (var i=0; i<this.tabs.length; i++){

			this.tabs[i].tabposition=i //remember position of tab relative to its peers

			if (this.tabs[i].getAttribute("rel")){

				var tabinstance=this

				this.hottabspositions[this.hottabspositions.length]=i //store position of "hot" tab ("rel" attr defined) relative to its peers

				this.subcontentids[this.subcontentids.length]=this.tabs[i].getAttribute("rel") //store id of sub content ("rel" attr value)

				this.tabs[i].onclick=function(){

					tabinstance.expandtab(this)

					tabinstance.cancelautorun() //stop auto cycling of tabs (if running)

					return false

				}

				if (this.tabs[i].getAttribute("rev")){ //if "rev" attr defined, store each value within "rev" as an array element

					this.revcontentids=this.revcontentids.concat(this.tabs[i].getAttribute("rev").split(/\s*,\s*/))

				}

				if (selectedtabfromurl==i || this.enabletabpersistence && selectedtab==-1 && parseInt(persistedtab)==i || !this.enabletabpersistence && selectedtab==-1 && this.getselectedClassTarget(this.tabs[i]).className=="selected"){

					selectedtab=i //Selected tab index, if found

				}

			}

		} //END for loop

		if (selectedtab!=-1) //if a valid default selected tab index is found

			this.expandtab(this.tabs[selectedtab]) //expand selected tab (either from URL parameter, persistent feature, or class="selected" class)

		else //if no valid default selected index found

			this.expandtab(this.tabs[this.hottabspositions[0]]) //Just select first tab that contains a "rel" attr

		if (parseInt(this.automodeperiod)>500 && this.hottabspositions.length>1){

			this.autoruntimer=setInterval(function(){tabinstance.autorun()}, this.automodeperiod)

		}

	} //END int() function



} //END Prototype assignment