function Pager(tableName, itemsPerPage) {
    this.tableName = tableName;
    this.itemsPerPage = itemsPerPage;
    this.currentPage = 1;
    this.pages = 0;
    this.inited = false;
    
    this.showRecords = function(from, to) {        
        var rows = document.getElementById(tableName).rows;
        // i starts from 1 to skip table header row
        for (var i = 1; i < rows.length; i++) {
            if (i < from || i > to)  
                rows[i].style.display = 'none';
            else
                rows[i].style.display = '';
        }
    }
    
    this.showPage = function(pageNumber) {
        
    	if (! this.inited) {
    		alert("not inited");
    		return;
    	}

        var oldPageAnchor = document.getElementById('pg'+this.currentPage);
        oldPageAnchor.className = 'pg-normal';
        
        this.currentPage = pageNumber;
        var newPageAnchor = document.getElementById('pg'+this.currentPage);
        newPageAnchor.className = 'pg-selected';
        
        $.cookie("all_paperPaging",this.currentPage);  

        var from = (pageNumber - 1) * itemsPerPage + 1;
        var to = from + itemsPerPage - 1;
        this.showRecords(from, to);
    }   
    
    this.prev = function() {
        if (this.currentPage > 1)
            this.showPage(this.currentPage - 1);
    }
    
    this.next = function() {
        if (this.currentPage < this.pages) {
            this.showPage(this.currentPage + 1);
        }
    }                        
    
    this.init = function() {
        var rows = document.getElementById(tableName).rows;
        var records = (rows.length - 1); 
        this.pages = Math.ceil(records / itemsPerPage);
        this.inited = true;

    }

    this.showPageNav = function(pagerName, positionId) {
    	if (! this.inited) {
    		alert("not inited");
    		return;
    	}
    	var element = document.getElementById(positionId);
    	
    	var pagerHtml = '<span onclick="' + pagerName + '.prev();" class="pg-normal"> &#171 Prev </span> | ';
        for (var page = 1; page <= this.pages; page++) 
            pagerHtml += '<span id="pg' + page + '" class="pg-normal" onclick="' + pagerName + '.showPage(' + page + ');">' + page + '</span> | ';
        pagerHtml += '<span onclick="'+pagerName+'.next();" class="pg-normal"> Next &#187;</span>';            
        
        element.innerHTML = pagerHtml;
    }
}
function navigation_buttons(totalItems,head)
{
 
    var numberOfButtons = 0;
    if(totalItems<=6){numberOfButtons = 0;}
    else if(totalItems>5 && totalItems<=10){numberOfButtons = 2;}
    else if(totalItems>10 && totalItems<=20){numberOfButtons = 3; }
    else if(totalItems>20 && totalItems<=50){numberOfButtons = 4;}
    else{ numberOfButtons = 5;}
   
     var buttons=new Array();
     buttons[0] = 5;
     buttons[1] = 10;
     buttons[2] = 20;
     buttons[3] = 50;
     buttons[4] = 100;
     var str = '';

     for(i=0;i<numberOfButtons;i++){
       var itempp = head + buttons[i];
       var strNew ='<input id="bt'+buttons[i]+'" class="itemperpage" type="button" value="'+buttons[i]+'" onClick="return (changeItemPerpage('+itempp+','+head+'))" />';
       str =str+strNew;
    }

    if(numberOfButtons>0)
        $("#itemPerPage").html('<p> Items per page: '+str+'</p>');
    if(head==1)
        itemsPerPage =itemsPerPage-1;
    $("#bt"+itemsPerPage).addClass("itemSelected");

}
function changeItemPerpage(itemsPerPage1,head)
{
     pager = new Pager('results', itemsPerPage1);
     pager.init();
     pager.showPageNav('pager', 'pageNavPosition');
     pager.showPage(1);
     if(head==1)
        itemsPerPage1 =itemsPerPage1-1;
     $("#bt"+itemsPerPage1).addClass("itemSelected");
     var buttons=new Array();
     buttons[0] = 5;
     buttons[1] = 10;
     buttons[2] = 20;
     buttons[3] = 50;
     buttons[4] = 100;
     for(i=0;i<buttons.length;i++){
         if(buttons[i]!=itemsPerPage1){
               $("#bt"+buttons[i]).addClass("itemperpage");
               $("#bt"+buttons[i]).removeClass("itemSelected");
         }
     }
}