is there a way instead of cftry catch, if authentication failed for cflap, i can show in an alert or not

@mk, It has been a long while since I dealt with LDAP. From memory I am pretty sure that we did another / 2nd query that required a successful authentication. (again from memory) - I think it was get the groups for the logged in user. But hopefully you'll think of / know of an appropriate query... Anyway - then check that query's result / resultcode - to determine if the login was successful. If so - great If not - show your error. (JS alert / bootstrap error message / your JS library of choice / etc)

CFLDAP will always throw an exception on failed authentication so it will require a try/catch or error handler elsewhere in your application to handle it.