pagination : Uncaught TypeError: Cannot set property 'className' of null
<p>I am trying to pagination to display data. The total number of records present are 19, I wanted to display 3 records initially.</p>

<p>This is my pagination code:</p>

<pre><code>// Instantiate pagination after data is available    
pager = new Pager('results', 3);
pager.init();
pager.showPageNav('pager', 'pageNavPosition');
pager.showPage(1);

// pagination object codes.
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 = total_records;
        // i starts from 1 to skip table header row
        for (var i = 1; i &lt; rows.length; i++) {
            if (i &lt; from || i &gt; 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 &gt; 1) this.showPage(this.currentPage - 1);
    }

    this.next = function () {
        if (this.currentPage &lt; this.pages) {
            this.showPage(this.currentPage + 1);
        }
    }

    this.init = function () {
        var rows = total_records;
        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 = '&lt;span onclick="' + pagerName + '.prev();" class="pg-normal"&gt; &amp;#171 Prev &lt;/span&gt; | ';
        for (var page = 1; page &lt;= this.pages; page++)
            pagerHtml += '&lt;span id="pg' + page + '" class="pg-normal" onclick="' + pagerName + '.showPage(' + page + ');"&gt;' + page + '&lt;/span&gt; | ';
        pagerHtml += '&lt;span onclick="' + pagerName + '.next();" class="pg-normal"&gt; Next &amp;#187;&lt;/span&gt;';
        element.innerHTML = pagerHtml;
    }
}
</code></pre>

<p>This is my <strong><a href="https://jsfiddle.net/48dxxm6o/37/">jsFiddle</a></strong>.</p>

<p>Could you please let me know how to resolve the issue coming in browser console?</p>

<blockquote>
  <p>Uncaught TypeError: Cannot set property 'className' of null </p>
</blockquote>