function imageToggle(img, onoff)
{   /*Function to swap an image based upon a mouse-over event.  Image must have two versions name.gif and nameOver.gif 
      Call example: onmouseover="imageToggle(this,'on');" onmouseout="imageToggle(this,'off');" */
    var myRegExp;
    if (document.images)
    {
        if (onoff=="on")
        { 
            myRegExp=/.gif/;
            img.src = img.src.replace(myRegExp,"Over.gif");
        } else { 
            myRegExp=/Over.gif/;
            img.src = img.src.replace(myRegExp,".gif");
        }
    }
}