function WM_preloadImages() {

  // Don't bother if there's no document.images
  if (document.images) {
    if (typeof document.WM == 'undefined'){
      document.WM = new Object();
    }
    document.WM.loadedImages = new Array();
    // Loop through all the arguments.
    var argLength = WM_preloadImages.arguments.length;
    for(arg=0;arg<argLength;arg++) {
      // For each arg, create a new image.
      document.WM.loadedImages[arg] = new Image();
      // Then set the source of that image to the current argument.
      document.WM.loadedImages[arg].src = WM_preloadImages.arguments[arg];
    }
  }
}

function WM_imageSwap(daImage, daSrc){

  if(document.images){
    if ((typeof daImage == 'string') || (typeof daImage == 'number')) {
      document.images[daImage].src = daSrc;
      // Or if an object reference was used, make sure it's an image.
    } else if (daImage && daImage.src) {
      daImage.src = daSrc;
    }
  }
}