I am using jquery validate plugin to validate (o'rly ?) a form, but i would like to custom success message for only one field (label).

It's for a username check, if the username is free, i want to have a custom message displayed like "Username is available". 

I tried to use onchange or success from remote call, but when i hook like this i have strange behavior, for example, the field doesn't validate anymore.

How would you achieve this ?

Thanks for your help.