function WM_preloadImages() {
  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){
  var objStr,obj;
  // 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(daImage) == 'string') {
      // This is for compatibility
      // with ie3 for the mac.
	  objStr = 'document.' + daImage;
      obj = eval(objStr);
      obj.src = daSrc;
      } else if ((typeof(daImage) == 'object') && daImage && daImage.src) {
        daImage.src = daSrc;
	  }	
  }
}
function bgImageSwap(elem, daSrc){
	elem.style.backgroundImage = "url('"+daSrc+"')";
}
WM_preloadImages('images/aaa_whiteButton.gif','images/aaa_greyButton.gif');