[imp] appending domains to usernames

[Tom Stockton]

Hi

I run an instance of imp that authenticates usernames of the form

username at mydomain.com

and

username at myotherdomain.com

I'd like to offer the users the ability to type in the 'username' part only 
and then select from a drop down box / radio button one of the two 
available domains.  This would then automatically append it to the username 
and then authenticate successfully.

Anybody know if this is feasible.

TIA

Tom