javascript alternating color rows of tables
<p>I have a page with several tables on it with the same class name.  I want to alternate the colors of the rows of every table on this page.  I'm using the code below with .  This code isn't working correctly, because only 1 table is alternating colors at a time (the first table).  what am I doing wrong?  All the tables on my page has "mytable" class.</p>

<pre><code>function altrows(classname,firstcolor,secondcolor)
{
    var tableElements = document.getElementsByClassName(classname) ;
    for(var j= 0; j &lt; tableElements.length; j++)
    {
        var table = tableElements[j] ;

        var rows = table.getElementsByTagName("tr") ;
        for(var i = 0; i &lt; rows.length; i=i+2)
        {
            rows[i].bgColor = firstcolor ;
            rows[i+1].bgColor = secondcolor ;
        }
    }
}
</code></pre>
