The Javascript use in the page :
if (navigator.appName == "Netscape" || (navigator.appName == "Microsoft Internet Explorer" && navigator.appVersion.substring(17, 25) == "MSIE 8.0")) {
$get('<%= Panel1.ClientID %>').style.width = '600px';
$get('<%= Panel2.ClientID %>').style.width = '600px';
$get('<%= Panel3.ClientID %>').style.width = '600px';
$get('<%= Map1.ClientID %>').style.width = '600px';
}
else {
$get('<%= Panel1.ClientID %>').style.width = '100%';
$get('<%= Panel2.ClientID %>').style.width = '100%';
$get('<%= Panel3.ClientID %>').style.width = '100%';
$get('<%= Map1.ClientID %>').style.width = '100%';
}
The declaration of the element :