function Pager(tableName, itemsPerPage, instance) {
    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'+instance+this.currentPage);
        oldPageAnchor.className = 'pg-normal';
        
        this.currentPage = pageNumber;
        var newPageAnchor = document.getElementById('pg'+instance+this.currentPage);
        newPageAnchor.className = 'pg-selected';
        
        var from = (pageNumber - 1) * itemsPerPage + 1;
        var to = from + itemsPerPage - 1;
        this.showRecords(from, to);
		
		if (pageNumber==this.pages && pageNumber==1) {
			document.getElementById('pgSpace'+instance).style.display = 'none';
		}
		else {
			if (pageNumber == this.pages) {
				document.getElementById('pgNext'+instance).style.color = 'gray';
				document.getElementById('pgNext'+instance).style.cursor = 'default';
			} else {
				document.getElementById('pgNext'+instance).style.color = 'black';
				document.getElementById('pgNext'+instance).style.cursor = 'pointer';
			}
			if (pageNumber == 1) {
				document.getElementById('pgPrev'+instance).style.color = 'gray';
				document.getElementById('pgPrev'+instance).style.cursor = 'default';
			} else {
				document.getElementById('pgPrev'+instance).style.color  = 'black';
				document.getElementById('pgPrev'+instance).style.cursor = 'pointer';
			}
		}
    }   
    
    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 = '<div id="pgSpace' + instance + '"><table width="100%" border="0" class="results_pages"><tr><td colspan="3" class="results_pages_border">&nbsp;</td></tr><tr><td colspan="3" class="location_nolink" align="center"><strong>More Results</strong></td></tr><tr><td align="left" width="40"><span id="pgPrev' + instance + '" onclick="' + pagerName + '.prev();" class="pg-normal">Prev</span></td><td align="center">|';
		for (var page = 1; page <= this.pages; page++) {
			pagerHtml += '<span id="pg' + instance + page + '" class="pg-normal" onclick="' + pagerName + '.showPage(' + page + ');">' + page + '</span>|';
		}
		pagerHtml += '</td><td align="right" width="40"><span  id="pgNext' + instance + '" onclick="' + pagerName + '.next();" class="pg-normal">Next</span></td></tr></table></div>';
		element.innerHTML = pagerHtml;
    }
}