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);
//        else {
//            this.showPage(this.pages);
//        }
//    }

//    this.next = function() {
//        if (this.currentPage < this.pages) {
//            this.showPage(this.currentPage + 1);
//        }
//        else {
//            this.showPage(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, pageNumbersID) {
        if (!this.inited) {
            alert("not inited");
            return;
        }
        var element = document.getElementById(positionId);
        var pagenumberElement = document.getElementById(pageNumbersID);
        var pageNumberHtml = "";
        //
        var pagerHtml = '<span class="prevImage" onclick="' + pagerName + '.prev();" class="pg-normal">&nbsp;&nbsp; </span>  ';
        for (var page = 1; page <= this.pages; page++)
            pageNumberHtml += '<span id="pg' + page + '" class="pg-normal" onclick="' + pagerName + '.showPage(' + page + ');">' + page + '</span> | ';
        pagerHtml += '<span class="nextImage" onclick="' + pagerName + '.next();" class="pg-normal">&nbsp;&nbsp; </span>';
        //pagenumberElement.innerHTML = pageNumberHtml;
        element.innerHTML = pagerHtml;
    }
}