function initImageRollOvers()
    {
     if (Boolean(document.getElementsByTagName))
      {
       img = document.getElementsByTagName('img');
       preload = new Array();
       for (var i = 0; i < img.length; i++) 
        {
         var src_out = img[i].src;
         if (src_out.indexOf('_out') != -1)
          {
           var src_over       = src_out.replace('_out', '_over');
           img[i].src_over    = src_over;
           img[i].src_out     = src_out;
           img[i].onmouseover = function () {this.src = this.src_over;}
           img[i].onmouseout  = function () {this.src = this.src_out;}
           preload[i] = new Image;
           preload[i].src = img[i].src_over;
          }
        }
      }  
    }
 
   window.onload = initImageRollOvers;