javascript type ahead

[leisse]

I have a few text boxes on my form, including one for a username and one for an email address. Both textboxes are the same with the exception of the @domain on the end of the email address. What I want to do is force the user to enter the username, and when they move to the next text box, have that username prepopulated in the email address text box. For example, after I type the username "leisse" in the username text area and I move onto to say the birthdate text area, I want "leisse" to automatically show up in the email address text area and I will append the @domain to the username. Any suggestions?

[redhead]

<script language="JavaScript">
function populate(text)
{
     document.my_form.email.value = text + "@domain";
}
</script>
<form name="my_form" action="what_ever" method="post">
<input type="text" name="name" value="" onUnFocus="javascript:populate(this.value)"> 
<input type="password" name="password" value=''>
<input type="text" name="email" value="">
</form>

Should give you an idear.