Is it possible to create a form that will link to join.cgi and insert the users selected username and/or domain into the fields on the sign up page?

I tried something like this:

<form name="form" method="post" action="http://example.com/cgi-bin/webmail/user/join.cgi?t=default">
<input type="text" name="username">@example.com
<input type="submit" name="Submit" value="Submit">
</form>

But all it does is ask for the reg code and no signup form.


Regards

Jason