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';
        
        //alert(newPageAnchor.id);
              
	var totalPage = "pg" + this.pages;	
        if(newPageAnchor.id == "pg1"){
//        	document.getElementById('pg-prev').className = "pg-selected";
        	document.getElementById('pg-next').className = "pg-normal";        	
        } else if(newPageAnchor.id == totalPage){        
  //      	document.getElementById('pg-prev').className = "pg-normal";
        	document.getElementById('pg-next').className = "pg-selected";        
        } else {
    //    	document.getElementById('pg-prev').className = "pg-normal";
        	document.getElementById('pg-next').className = "pg-normal";
        }
                
        var from = (pageNumber - 1) * itemsPerPage + 1;
        var to = from + itemsPerPage - 1;

		this.showRecords(from, to);
		this.drawSummary(pageNumber);
    }   
    
	this.drawSummary = function(pageNumber) {
		document.getElementById("summaryElem").innerHTML = "<span>PAGE " + pageNumber + " OF " + this.pages + "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span></div>";
	}
	
    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.last = function() {
            this.showPage(this.pages);
    }     
    
    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 = '<div id="summaryElem"><span>PAGE 1 OF ' + this.pages +'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span></div><div id="pageElem">';

// pagerHtml += '<span id="pg-prev" 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 id="pg-next" onclick="'+pagerName+'.last();" class="pg-normal"> Last &#187;</span></div>';            
                
//        alert(pagerHtml);
        element.innerHTML = pagerHtml;
    }
}