Merhabalar,

Sanırım şöyle:

<!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" dir="ltr" lang="tr-TR">

<head>
	<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
	
<style type="text/css">
html,body {
	width:99%;
	height:95%;
	}
</style>
</head>
<body>
<iframe frameborder="0" scrolling="auto" src="http://www.google.com.tr" style="width:100%;height:100%"></iframe>
</body>
</html>
Saygılarımla;
Samet ARAS.