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