Imagine a simple PHP page with a password input field. The entered password goes into a $_POST variable and will be checked against a hash value on the server side. Very rudimentary.

Now what I need is that depending of whether the entered password is correct or incorrect a JavaScript (like this) should be executed first. Only after should the server do whatever it's supposed to do. For security reasons I don't want the hash value to be publish in the JavaScript.

How do you do that?