Launching a pop up?

Hi

When someone registers for my site they are forwarded to _register_sucess.htm When this happens I would like a pop up to launch on page loading?
could someone PLEASE help me with the code?

Check out New window and fields below. Note: the code says java script. It should be javascript (one word) Good luck

Hi,
modify templates\register_success.htmfile for this.
Put this code there:

<script language=javascript>

alert("Registered!");

</script>