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';
        
        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.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';

        var from = (pageNumber - 1) * itemsPerPage + 1;
        var to = from + itemsPerPage - 1;
        this.showRecords(from, to);
        
        var pgNext = document.getElementById('pgNext');
        var pgPrev = document.getElementById('pgPrev');
        var pg1 = document.getElementById('pg1');
        if (this.currentPage == this.pages){
            pgNext.style.color = 'grey';
        }else{
            pgNext.style.color = '';
		}
		if (this.currentPage == 1){
            pgPrev.style.color = 'grey';
            pg1.style.color = 'grey';
        }else{
            pgPrev.style.color = '';
		}
		
		
		if (this.currentPage == this.currentPage){
            newPageAnchor.style.color = 'grey';
            oldPageAnchor.style.color = 'black';
        }else{
            newPageAnchor.style.color = 'grey';
		}
		
    }
    this.showPageNav = function(pagerName, positionId ) {
    	if (! this.inited) {
    		alert("not inited");
    		return;
    	}
		var selected = "";
		
    	var element = document.getElementById(positionId);

    	var pagerHtml = '<span id="pgPrev" onclick="' + pagerName + '.prev();" class="pg-normal" style="font-weight:bold; cursor: pointer; cursor: hand;"> &#171 Prev </span> | ';
		
        for (var page = 1; page <= this.pages; page++){
            pagerHtml += '<span  id="pg' + page + '" class="pg-normal" style="font-weight:bold; cursor: pointer; cursor: hand;" onclick="' + pagerName + '.showPage(' + page + ');"> ' + page + '</span> | ';
			
			}
        pagerHtml += '<span id="pgNext" onclick="'+pagerName+'.next();" class="pg-normal" style="font-weight:bold;  cursor: pointer; cursor: hand;"> Next &#187;</span>';            

        element.innerHTML = pagerHtml;
    }
/*
    this.showPageNav = function(pagerName, positionId) {
    	if (! this.inited) {
    		alert("not inited");
    		return;
    	}
    	var element = document.getElementById(positionId);
    	
    	var pagerHtml = '<span onclick="' + pagerName + '.prev();" style="cursor: pointer; cursor: hand;" class="pg-normal"> &#171 Prev </span> | ';
        for (var page = 1; page <= this.pages; page++) 
            pagerHtml += '<span id="pg' + page + '" class="pg-normal" style="cursor: pointer; cursor: hand;" onclick="' + pagerName + '.showPage(' + page + ');">' + page + '</span> | ';
        pagerHtml += '<span onclick="'+pagerName+'.next();" style="cursor: pointer; cursor: hand;" class="pg-normal"> Next &#187;</span>';            
        
        element.innerHTML = pagerHtml;
    } */
}