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).childNodes;
        // i starts from 1 to skip table header row
        for (var i = 0; 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) {
    		return;
    	}

        var oldPageAnchor = document.getElementById('pg'+this.currentPage);
        if (oldPageAnchor) {
        	oldPageAnchor.className = 'pg-normal';
        }

        this.currentPage = pageNumber;
        var newPageAnchor = document.getElementById('pg'+this.currentPage);
        if (newPageAnchor) {
        	newPageAnchor.className = 'pg-selected';
        }

        var from = (pageNumber - 1) * itemsPerPage;// + 1;
        var to = from + itemsPerPage - 1;
        this.showRecords(from, to);

        
        if (pageNumber == 1) {
            if (document.getElementById('prev-' + this.tableName)) {
                document.getElementById('prev-' + this.tableName).style.visibility="hidden";
            }
            if (document.getElementById('next-' + this.tableName)) {
                document.getElementById('next-' + this.tableName).style.visibility="visible";
            }
        } else {
            document.getElementById('prev-' + this.tableName).style.visibility="visible";
            if (pageNumber == this.pages) {
                document.getElementById('next-' + this.tableName).style.visibility="hidden";
            } else {
                document.getElementById('next-' + this.tableName).style.visibility="visible";
            }
        }


    }

    this.prev = function() {
        if (this.currentPage > 0)
            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).childNodes;
        var records = (rows.length);
        this.pages = Math.ceil(records / itemsPerPage);
        this.inited = true;
    }

    this.showPageNav = function(pagerName, positionId) {

        var element = document.getElementById(positionId);
        if (this.pages > 1) {
        if (!this.inited) {
    		return;
    	}

    	var pagerHtml = '<a onclick="' + pagerName + '.prev();" class="pg-normal" id="prev-' + this.tableName + '"> &#171 Prev </a>';
        for (var page = 1; page <= this.pages; page++) {
            pagerHtml += '<a id="pg' + page + '"  class="pg-normal" onclick="' + pagerName + '.showPage(' + page + ');">' + page + '</a>';
        }
        pagerHtml += '<a onclick="'+pagerName+'.next();" class="pg-normal" id="next-' + this.tableName + '"> Next &#187;</a>';

        element.innerHTML = pagerHtml;
        } else {
            element.innerHTML = '';
        }
    }
}