html rollover map

hi there. me doing rollover image map with mouseover and onclick. there is a backround image and few same sized transparent layers with some pics on them. few poly areas. ones with onclick should stay when i move my cursor on others, they should change only with other onclick.

so onclick images should stay and onmouseover layers should just load on them.

<area shape="rect" coords="" onClick="if(document.images) document.getElementById('map').src= 'clicklayer.png"  />
 
<area shape="poly" coords="" onMouseOver="if(document.images) document.getElementById('Map').src= 'mouselayer.png';" onMouseOut="if(document.images) document.getElementById('Map').src= 'blank.png';"  />

whats the easiest way?

>>6
thanks. but it worked in a lot easier way.
its like a second background layer over the first one.

document.getElementById('Maps').style.backgroundImage='url(clicklayer.png)'