var wstat
function popup(image,tailleX,tailleY) {
var top=(screen.height-tailleY)/2;
var left=(screen.width-tailleX)/2;

wstat=window.open('zoom.htm?image='+image,'walt','width='+tailleX+',height='+tailleY+',top='+top+',left='+left+',toolbar=no,scrollbars=no,resizable=no')
}