var dom = net = iex = false;
if (document.getElementById) dom = true; // IE5+ ou Netscape6+/Mozilla
if (document.layers) net = true; // Netscape4
if (document.all) iex = true; // IE4+

if (iex) {
  var larg_utile = "document.body.offsetWidth";
  var haut_utile = "document.body.offsetHeight";
}
else if (dom || net) {
  var larg_utile = "window.innerWidth";
  var haut_utile = "window.innerHeight";
}
else {}

function resize(e){
	if (eval(larg_utile)<1000) {
		document.getElementById('webvidi').style.width = "990px";
	} else {
		document.getElementById('webvidi').style.width = "100%";
	}
	if (eval(haut_utile)<540) {
		document.getElementById('webvidi').style.height = "539px";
	} else {
		document.getElementById('webvidi').style.height = "99%";
	}
}
window.onresize = resize;
window.onload = resize;