var tabArray = null;
var contentArray = null;
var tdContent = document.getElementById("tdContent");

function ChangeTab(sender)
{
    /* Set new content, remove old content */
    for (var i = 0; i < tabArray.length; i++)
    {
        tabArray[i].src = tabArray[i].src.replace("_on", "");
        if (tabArray[i] == sender)
        {
            tabArray[i].src = tabArray[i].src.replace(".gif", "_on.gif");
            tdContent.innerHTML = contentArray[i].innerHTML;
        }
    }
}