Hi there biannucci,
and a warm welcome to these forums :)
IIKLOP's reply is almost OK. Assuming that windowHeight is a variable, it should be...
document.getElementById("divName").style.height = windowHeight - 100+"px";
Here is an example...
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>div size according to browser</title>
<meta http-equiv="Content-Type" content="application/xhtml+xml; charset=utf-8" />
<style type="text/css">
/*<![CDATA[*/
#divName {
border:solid 1px #000;
text-align:center;
}
/*//]]>*/
</style>
<script type="text/javascript">
//<![CDATA[
var windowWidth=screen.availWidth/2+"px";
var windowHeight=screen.availHeight/4*3+"px"
function sniffer() {
var el=document.getElementById("divName");
if(screen.width==1280) {
el.style.width=windowWidth;
el.style.height= windowHeight;
el.style.margin="auto";
}
else {
if(screen.width==1024) {
el.style.width=windowWidth;
el.style.height= windowHeight;
el.style.margin="auto";
}
else {
if(screen.width==800) {
el.style.width=windowWidth;
el.style.height= windowHeight;
el.style.margin="auto";
}
}
}
}
onload=sniffer;
//]]>
</script>
</head>
<body>
<div id="divName"></div>
</body>
</html>