Load panorama in background

Hi, I want to load panorama but hide it under a thumbnail image while it's being loaded in the background and show it only when a user clicks on the thumbnail. I have added a layer for thumbnail image and made it's onclick event to set visible=false for the layer.

The problem is that as soon the tour is loaded the image element shows up for a second and then the layer covers it up. I don't want the image element to show up as the tour is load.

Thanks.

<krpano>


 <layer name="thumbnail"
 	type="image"
 	url="%$thumbnailPath%"
 	keep="false"
 	background="false"
 	visible="true"
 	handcursor="false"
 	width="100%"
 	height="100%"
 	onclick="set(layer[blank].visible, false);"
 	/>




	<image>
    	<left  url="1.png"/>
    	<front url="2.png"/>
    	<right url="3.png"/>
    	<back  url="4.png"/>
    	<up	url="5.png"/>
    	<down  url="6.png"/>
	</image>


</krpano>