// JavaScript Document
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;
		//alert(rows.length);
        // 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.showPageNav = function(pagerName, positionId) {
     if (! this.inited) {
      alert("not inited");
      return;
     }
     var element = document.getElementById(positionId);
     
     var pagerHtml = '<div style="width:200px;text-align:right;"><div style="float:left; margin:0px auto; padding-right:0px; cursor:pointer;" onclick="' + pagerName + '.prev();" ><span class="txt_link">Prev</span></div>';
        for (var page = 1; page <= this.pages; page++)
            pagerHtml += '<div class="txt_link" style="float:left; margin:0px auto; padding-right:5px; margin-top:-3px; cursor:pointer;" id="pg' + page + '" onclick="' + pagerName + '.showPage(' + page + ');">' + page + '</div>';
        pagerHtml += '<div style="float:left; margin:0px auto; cursor:pointer;" onclick="'+pagerName+'.next();" ><span class="txt_link">Next</span></div></div>';           
       
        element.innerHTML = pagerHtml;
    }
}