Some Help

[KumbhaniMehul]

I have one registration form,in that one username field,
when user fill this text box and click on the "Check Availability" then my servlet have to check that user is exist or not.

and i want one boolean answer (true/false).

Have any other trick to fulfill my requirement?..

[jkmyoung]

Where are you storing usernames? Are you accessing a backend database somehow?

[KumbhaniMehul]

Where are you storing usernames? Are you accessing a backend database somehow?

Yes, I have User_Details table and i have stored UserName field in this table.
I want to check that name is available or not?
In my table UserName is primary key.

[jkmyoung]

Please excuse my denseness, but I'm still uncertain as to with what part you're having the problem.
name = textBox.Text();

"select *
from User_Details
where UserName = '"+name+"'

if results exist, then the name exists.