Image Zoom

I have this script:

Code:

<script>
var nW,nH,oH,oW;
function zoomToggle(iWideSmall,iHighSmall,iWideLarge,iHighLarge,whichImage){
oW=whichImage.style.width;oH=whichImage.style.height;
if((oW==iWideLarge)||(oH==iHighLarge)){
nW=iWideSmall;nH=iHighSmall;}else{
nW=iWideLarge;nH=iHighLarge;}
whichImage.style.width=nW;whichImage.style.height=nH;
}
</script>

But it requires me to post a image using HTML tags

I want the members to be able to post images that can be zoomed when clicked