var browserName=navigator.appName; 
if (browserName=="Netscape")
{ 
 var IFheight="400";
 var IFwidth="100%";
}
else 
{ 
 if (browserName=="Microsoft Internet Explorer")
 {
 var IFheight="90%";
 var IFwidth="95%";
 }
 else
  {
 var IFheight="600";
 var IFwidth="400";
   }
}