questo e' il codice giusto

<html>
<head>
<meta http-equiv="refresh" content="20"; URL="http://michiross.altervista.org/redirect.php">
</head>
<body>
<?php
$time=gmdate("H:i");
echo($time);
if($time=="21:18"){
echo "<script type='text/javascript'>"."window.open('www.mysite.com');</script>";
}
?>
</body>
</html>