function imageSwap(imgName, imgSrc){
  var objStr,obj;
  /* Usage: imageSwap(originalImage, 'newSourceUrl'); */

  // Check to make sure that images are supported in the DOM.
  if(document.images){
    // Check to see whether you are using a name, number, or object
    if (typeof(imgName) == 'string') {
      // This whole objStr nonesense is here solely to gain compatability
      // with ie3 for the mac.
      objStr = 'document.' + imgName;
      obj = eval(objStr);
      obj.src = imgSrc;
    } else if ((typeof(daImage) == 'object') && imgName && imgName.src) {
      imgName.src = imgSrc;
    }
  }
}