var ajaxpageclass=new Object()
ajaxpageclass.loadstatustext="<div style='text-align:center; width:95%'><img src='"+siteName+"images/loading.gif' /></div>"  // HTML to show while requested page is being fetched:
ajaxpageclass.ajaxbustcache=false // Bust cache when fetching pages?
ajaxpageclass.paginatepersist=false //enable persistence of last viewed pagination link (so reloading page doesn't reset page to 1)?
ajaxpageclass.pagerange=10 // Limit page links displayed to a specific number (useful if you have many pages in your book)?
ajaxpageclass.ellipse=" ... " // Ellipse text (no HTML allowed)

/////////////// No need to edit beyond here /////////////////////////
ajaxpageclass.connect=function(pageurl, divId){
    var page_request = false
    var bustcacheparameter=""
    if (window.XMLHttpRequest && !document.all) // if Mozilla, Safari etc (skip IE7, as object is buggy in that browser)
        page_request = new XMLHttpRequest()
    else if (window.ActiveXObject){ // if IE6 or below
        try {
            page_request = new ActiveXObject("Msxml2.XMLHTTP")
        }
        catch (e){
            try{
                page_request = new ActiveXObject("Microsoft.XMLHTTP")
            }
            catch (e){}
        }
    }
    else
        return false
    document.getElementById(divId).innerHTML=this.loadstatustext //Display "fetching page message"
    page_request.onreadystatechange=function(){
        ajaxpageclass.loadpage(page_request, divId)
        }
    if (this.ajaxbustcache) //if bust caching of external page
        bustcacheparameter=(pageurl.indexOf("?")!=-1)? "&"+new Date().getTime() : "?"+new Date().getTime()
    page_request.open('GET', pageurl+bustcacheparameter, true)
    page_request.send(null)
}

ajaxpageclass.loadpage=function(page_request, divId){
    if (page_request.readyState == 4 && (page_request.status==200 || window.location.href.indexOf("http")==-1)){
        document.getElementById(divId).innerHTML=page_request.responseText
    }
}

ajaxpageclass.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 null
}

ajaxpageclass.setCookie=function(name, value){
    document.cookie = name+"="+value
}

ajaxpageclass.getInitialPage=function(divId, pageinfo){
    var persistedpage=this.getCookie(divId)
    var selectedpage=(this.paginatepersist && this.getCookie(divId)!=null)? parseInt(this.getCookie(divId)) : pageinfo.selectedpage
    return (selectedpage>pageinfo.pages.length-1)? 0 : selectedpage //check that selectedpage isn't out of range
}

ajaxpageclass.createBook=function(pageinfo, divId, paginateIds){ //MAIN CONSTRUCTOR FUNCTION
    this.pageinfo=pageinfo //store object containing URLs of pages to fetch, selected page number etc
    this.divId=divId
    this.paginateIds=paginateIds
    this.paginateInfo={
        divs:[],
        pagelinks:[[]],
        prevlink:[],
        nextlink:[],
        previouspage:null,
        previousrange:[null,null],
        leftellipse:[],
        rightellipse:[]
    }
    this.dopagerange=false
    this.pagerangestyle=''
    this.ellipse='<span style="display:none">'+ajaxpageclass.ellipse+'</span>' //construct HTML for ellipse
    var initialpage=ajaxpageclass.getInitialPage(divId, pageinfo)
    this.buildpagination(initialpage)
    this.selectpage(initialpage)
}

ajaxpageclass.createBook.prototype={

    buildpagination:function(selectedpage){ //build pagination links based on length of this.pageinfo.pages[]
        this.dopagerange=(this.pageinfo.pages.length>ajaxpageclass.pagerange) //Bool: enable limitpagerange if pagerange value is less than total pages available
        this.pagerangestyle=this.dopagerange? 'style="display:none"' : '' //if limitpagerange enabled, hide pagination links when building them
        this.paginateInfo.previousrange=null //Set previousrange[start, finish] to null to start
        if (this.pageinfo.pages.length<=1){ //no 0 or just 1 page
            document.getElementById(this.paginateIds[0]).innerHTML= ""
            return
        }
        else{ //construct paginate interface
            var paginateHTML='<div class="pagination"><ul>\n'
            paginateHTML+='<li><a href="#previous" rel="'+(selectedpage-1)+'">&lt;&lt;</a></li>\n' //previous link HTML
            for (var i=0; i<this.pageinfo.pages.length; i++){
                var ellipses={
                    left: (i==0? this.ellipse : ''),
                    right: (i==this.pageinfo.pages.length-1? this.ellipse : '')
                    } //if this is 1st or last page link, add ellipse next to them, hidden by default
                paginateHTML+='<li>'+ellipses.right+'<a href="#page'+(i+1)+'" rel="'+i+'" '+this.pagerangestyle+'>'+(i+1)+'</a>'+ellipses.left+'</li>\n'
            }
            paginateHTML+='<li><a href="#next" rel="'+(selectedpage+1)+'">&gt;&gt;</a></li>\n' //next link HTML
            paginateHTML+='</ul></div>'
        }// end construction
        this.paginateInfo.previouspage=selectedpage //remember last viewed page
        for (var i=0; i<this.paginateIds.length; i++){ //loop through # of pagination DIVs specified
            var paginatediv=document.getElementById(this.paginateIds[i]) //reference pagination DIV
            this.paginateInfo.divs[i]=paginatediv //store ref to this paginate DIV
            paginatediv.innerHTML=paginateHTML
            var paginatelinks=paginatediv.getElementsByTagName("a")
            var ellipsespans=paginatediv.getElementsByTagName("span")
            this.paginateInfo.prevlink[i]=paginatelinks[0]
            if (paginatelinks.length>0)
                this.paginateInfo.nextlink[i]=paginatelinks[paginatelinks.length-1]
            this.paginateInfo.leftellipse[i]=ellipsespans[0]
            this.paginateInfo.rightellipse[i]=ellipsespans[1]
            this.paginateInfo.pagelinks[i]=[] //array to store the page links of pagination DIV
            for (var p=1; p<paginatelinks.length-1; p++){
                this.paginateInfo.pagelinks[i][p-1]=paginatelinks[p]
            }
            var pageinstance=this
            paginatediv.onclick=function(e){
                var targetobj=window.event? window.event.srcElement : e.target
                if (targetobj.tagName=="A" && targetobj.getAttribute("rel")!=""){
                    if (!/disabled/i.test(targetobj.className)){ //if this pagination link isn't disabled (CSS classname "disabled")
                        pageinstance.selectpage(parseInt(targetobj.getAttribute("rel")))
                    }
                }
                return false
            }
        }
    },

    selectpage:function(selectedpage){
        //replace URL's root domain with dynamic root domain (with or without "www"), for ajax security sake:
        if (this.pageinfo.pages.length>0){
            var ajaxfriendlyurl=this.pageinfo.pages[selectedpage].replace(/^http:\/\/[^\/]+\//i, "http://"+window.location.hostname+"/")
            ajaxpageclass.connect(ajaxfriendlyurl, this.divId) //fetch requested page and display it inside DIV
        }
        if (this.pageinfo.pages.length<=1) //if this book only contains only 1 page (or 0)
            return //stop here
        var paginateInfo=this.paginateInfo
        for (var i=0; i<paginateInfo.divs.length; i++){ //loop through # of pagination DIVs specified
            //var paginatediv=document.getElementById(this.paginateIds[i])
            paginateInfo.prevlink[i].className=(selectedpage==0)? "prevnext disabled" : "prevnext" //if current page is 1st page, disable "prev" button
            paginateInfo.prevlink[i].setAttribute("rel", selectedpage-1) //update rel attr of "prev" button with page # to go to when clicked on
            paginateInfo.nextlink[i].className=(selectedpage==this.pageinfo.pages.length-1)? "prevnext disabled" : "prevnext"
            paginateInfo.nextlink[i].setAttribute("rel", selectedpage+1)
            paginateInfo.pagelinks[i][paginateInfo.previouspage].className="" //deselect last clicked on pagination link (previous)
            paginateInfo.pagelinks[i][selectedpage].className="currentpage" //select current pagination link
        }
        paginateInfo.previouspage=selectedpage //Update last viewed page info
        ajaxpageclass.setCookie(this.divId, selectedpage)
        this.limitpagerange(selectedpage) //limit range of page links displayed (if applicable)
    },

    limitpagerange:function(selectedpage){
        //reminder: selectedpage count starts at 0 (0=1st page)
        var paginateInfo=this.paginateInfo
        if (this.dopagerange){
            var visiblelinks=ajaxpageclass.pagerange-1 //# of visible page links other than currently selected link
            var visibleleftlinks=Math.floor(visiblelinks/2) //calculate # of visible links to the left of the selected page
            var visiblerightlinks=visibleleftlinks+(visiblelinks%2==1? 1 : 0) //calculate # of visible links to the right of the selected page
            if (selectedpage<visibleleftlinks){ //if not enough room to the left to accomodate all visible left links
                var overage=visibleleftlinks-selectedpage
                visibleleftlinks-=overage //remove overage links from visible left links
                visiblerightlinks+=overage //add overage links to the visible right links
            }
            else if ((this.pageinfo.pages.length-selectedpage-1)<visiblerightlinks){ //else if not enough room to the left to accomodate all visible right links
                var overage=visiblerightlinks-(this.pageinfo.pages.length-selectedpage-1)
                visiblerightlinks-=overage //remove overage links from visible right links
                visibleleftlinks+=overage //add overage links to the visible left links
            }
            var currentrange=[selectedpage-visibleleftlinks, selectedpage+visiblerightlinks] //calculate indices of visible pages to show: [startindex, endindex]
            var previousrange=paginateInfo.previousrange //retrieve previous page range
            for (var i=0; i<paginateInfo.divs.length; i++){ //loop through paginate divs
                if (previousrange){ //if previous range is available (not null)
                    for (var p=previousrange[0]; p<=previousrange[1]; p++){ //hide all page links
                        paginateInfo.pagelinks[i][p].style.display="none"
                    }
                }
                for (var p=currentrange[0]; p<=currentrange[1]; p++){ //reveal all active page links
                    paginateInfo.pagelinks[i][p].style.display="inline"
                }
                paginateInfo.pagelinks[i][0].style.display="inline" //always show 1st page link
                paginateInfo.pagelinks[i][this.pageinfo.pages.length-1].style.display="inline" //always show last page link
                paginateInfo.leftellipse[i].style.display=(currentrange[0]>1)? "inline" : "none" //if starting page is page3 or higher, show ellipse to page1
                paginateInfo.rightellipse[i].style.display=(currentrange[1]<this.pageinfo.pages.length-2)? "inline" : "none" //if end page is 2 pages before last page or less, show ellipse to last page
            }
        }
        paginateInfo.previousrange=currentrange
    },

    refresh:function(pageinfo){
        this.pageinfo=pageinfo
        var initialpage=ajaxpageclass.getInitialPage(this.divId, pageinfo)
        this.buildpagination(initialpage)
        this.selectpage(initialpage)
    }
}