php iframe header跳轉

<frameset rows="51,*" cols="*" frameborder="no" border="0" framespacing="0">
  <frame src="top.php" name="topFrame" scrolling="No" noresize="noresize" id="topFrame" title="topFrame" />
  <frameset cols="208,*" frameborder="no" border="0" framespacing="0">
    <frame src="left.php" name="leftFrame" scrolling="No" noresize="noresize" id="leftFrame" title="leftFrame" />
    <frame src="mainfra.php" name="mainFrame" id="mainFrame" title="mainFrame" />
  </frameset>
</frameset>

php代碼如下，這樣寫就可以跳轉去父窗口

if(empty($_SESSION['loginuser'])){
    //header("Location:login/login.php");
    exit('<script language="javascript">top.location.href="login/login.php"</script>');
}else{
    $loginuser=$_SESSION['loginuser'];
}