Redirection with $_SERVER["PHP_SELF"] and using header()

is it possible to do this , im trying to validate a form then, it will redirect using header() if TRUE.. but it seems not to be working? or my method is completely wrong ?

if ($_SERVER["REQUEST_METHOD"] == "POST") {   $email = $_POST["clientEmail"];

  if ($email != $sentEmailClients)   {
    echo 'Please enter a valid email';   }   else{

    $newURL = "http://www.myurl.com";    header('Location: '.$newURL);   } }