Spry

Preload images

 To preload the images used for the down and right submenu arrows, add either the imgDown option, the imgRight option, or both options to the widget constructor, as follows: 
<script type="text/javascript">
	var mb1 = new Spry.Widget.MenuBar("menubar1", {imgDown:"SpryAssets/SpryMenuBarDownHover.gif", imgRight:"SpryAssets/SpryMenuBarRightHover.gif"});
</script>

Add the correct path to the image as the value for the option. This path varies depending on where you store the images.