function virtualpaginate(className, chunksize, elementType) {
	var elementType=(typeof elementType=="undefined")? "div" : elementType
	this.pieces=virtualpaginate.collectElementbyClass(className, elementType)

	this.chunksize=(typeof chunksize=="undefined")? 1 : (chunksize>0 && chunksize < this.pieces.length)? chunksize : this.pieces.length
	this.pagecount=Math.ceil(this.pieces.length/this.chunksize)

    this.showpage(-1)
	this.currentpage=0
	this.showpage(this.currentpage)
}


virtualpaginate.collectElementbyClass=function(classname, element){
	var classnameRE=new RegExp("(^|\\s+)"+classname+"($|\\s+)", "i")
	var pieces=[]
	var alltags=document.getElementsByTagName(element)
	for (var i=0; i < alltags.length; i++){

    if (typeof alltags[i].className=="string" && alltags[i].className.search(classnameRE)!=-1)
		pieces[pieces.length]=alltags[i]
	}

    return pieces
}

virtualpaginate.prototype.showpage=function(pagenumber) {
	var totalitems=this.pieces.length
	var showstartindex=pagenumber*this.chunksize
	var showendindex=showstartindex+this.chunksize-1


    for (var i=0; i < totalitems; i++) {
        if (i>=showstartindex && i<=showendindex)
            this.pieces[i].style.display="block"
        else
            this.pieces[i].style.display="none"
        }

    this.currentpage=parseInt(pagenumber)

    //this.check_page_number(this.currentpage);

    if (this.cpspan)
		this.cpspan.innerHTML='Pagina '+(this.currentpage+1)+' di ' + this.pagecount
}

virtualpaginate.prototype.check_page_number = function (page_number) {

    var instanceOfBox=this

    // alert(page_number + " : " + this.pagecount);

    if(page_number == 0) {
        this.previous_btn.style.visibility="hidden"
        this.first_btn.style.visibility="hidden"
        this.next_btn.style.visibility="visible"
        this.last_btn.style.visibility="visible"
    } else if(page_number == (this.pagecount-1)) {
        this.previous_btn.style.visibility="visible"
        this.first_btn.style.visibility="visible"
        this.next_btn.style.visibility="hidden"
        this.last_btn.style.visibility="hidden"
    } else {
        this.previous_btn.style.visibility="visible"
        this.first_btn.style.visibility="visible"
        this.next_btn.style.visibility="visible"
        this.last_btn.style.visibility="visible"
    }

}

virtualpaginate.prototype.paginate_build_selectmenu=function(paginatedropdown){
    var instanceOfBox=this
    this.selectmenupresent=1
    for (var i=0; i < this.pagecount; i++)
        paginatedropdown.options[i] = new Option("Pagina "+(i+1)+" di "+this.pagecount, i)
        paginatedropdown.selectedIndex=this.currentpage
        paginatedropdown.onchange=function(){
        instanceOfBox.showpage(this.selectedIndex)
    }
}


/**
 *      Assegna i metodi ai pulsanti di navigazione principali
 *
 *      @paginatelinks      array che contiene i pulsanti di navigazione
 */
virtualpaginate.prototype.paginate_build_regularlinks=function(paginatelinks){

    var instanceOfBox=this

    this.parse_navigation_link(paginatelinks)

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

    var currentpagerel = paginatelinks[i].getAttribute("rel")

    if (currentpagerel=="previous" || currentpagerel=="next" || currentpagerel=="first" || currentpagerel=="last")

        paginatelinks[i].onclick=function(){

            instanceOfBox.navigate(this.getAttribute("rel"))

            return false

        }

    }
}

virtualpaginate.prototype.parse_navigation_link = function(paginatelinks) {

    //this.paginate_build_regularlinks(paginatelinks);

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

        var currentpagerel = paginatelinks[i].getAttribute("rel")

        switch (paginatelinks[i].getAttribute("rel")) {
            case "previous":
                this.previous_btn = paginatelinks[i];
                break;

            case "next":
                this.next_btn = paginatelinks[i];
                break;

            case "first":
                this.first_btn = paginatelinks[i];
                break;

            case "last":
                this.last_btn = paginatelinks[i];
                break;



        }
    }

}


virtualpaginate.prototype.paginate_build_flatview=function(flatviewcontainer){

    var instanceOfBox=this

    var flatviewhtml=""

    for (var i=0; i < this.pagecount; i++) {
        flatviewhtml+='<a href="#flatview" rel="' + i + '">'+(i+1)+'</a>'

        if ( i < (this.pagecount-1)) {
          flatviewhtml+=' | '
        }
    }

    flatviewcontainer.innerHTML=flatviewhtml

    this.flatviewlinks = flatviewcontainer.getElementsByTagName("a")

    for (var i=0; i < this.flatviewlinks.length; i++){
        this.flatviewlinks[i].onclick = function() {
            instanceOfBox.flatviewlinks[instanceOfBox.currentpage].className=""

            this.className="selected"

            instanceOfBox.check_page_number(this.getAttribute("rel"))

            instanceOfBox.showpage(this.getAttribute("rel"))

            return false
        }
    }

    //alert("virtualpaginate.prototype.paginate_build_flatview")

    this.flatviewlinks[this.currentpage].className="selected"

    this.flatviewpresent=true
}

virtualpaginate.prototype.paginate_build_cpinfo=function(cpspan){
    this.cpspan=cpspan
    cpspan.innerHTML='Pagina '+(this.currentpage+1)+' di '+this.pagecount
}


/**
 *      Crea la paginazione
 *
 *      @divid      Div che contiene la paginazione
 */
virtualpaginate.prototype.buildpagination=function(divid){

    var instanceOfBox=this
    var paginatediv=document.getElementById(divid)

    if (this.chunksize==this.pieces.length){
        paginatediv.style.display="none"
        return
    }

    var paginationcode = paginatediv.innerHTML

    if (paginatediv.getElementsByTagName("select").length>0)
        this.paginate_build_selectmenu(paginatediv.getElementsByTagName("select")[0])

    if (paginatediv.getElementsByTagName("a").length>0)
        this.paginate_build_regularlinks(paginatediv.getElementsByTagName("a"))

    var allspans=paginatediv.getElementsByTagName("span")

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

        if (allspans[i].className=="flatview")
            this.paginate_build_flatview(allspans[i])
        else if (allspans[i].className=="paginateinfo")
            this.paginate_build_cpinfo(allspans[i])
    }

    this.paginatediv=paginatediv
}

virtualpaginate.prototype.navigate=function(keyword){

    if (this.flatviewpresent)
        this.flatviewlinks[this.currentpage].className=""

    if (keyword=="previous")
        this.currentpage=(this.currentpage>0)? this.currentpage-1 : (this.currentpage==0)? this.pagecount-1 : 0
    else if (keyword=="next")
        this.currentpage=(this.currentpage < (this.pagecount-1))? this.currentpage+1 : 0
    else if (keyword=="first")
        this.currentpage=0
    else if (keyword=="last")
        this.currentpage=this.pieces.length-1

    this.showpage(this.currentpage)

    this.check_page_number(this.currentpage)

    if (this.selectmenupresent)
        this.paginatediv.getElementsByTagName("select")[0].selectedIndex=this.currentpage

    if (this.flatviewpresent)
        this.flatviewlinks[this.currentpage].className="selected"
}