Return Errors on forms

[eluser]JayArias[/eluser]
I have a custom Auth Controller and Model , Is there a method I can use through validation that will tell the user what he didn't enter or if it's a wrong username or password.

[eluser]JoostV[/eluser]
Not sure what you mean. Validation of your forms (required|maxlength[], etc): check the form_validation library in the userguide

Wrong username/paswword combination: query the database for a user that has the existing username/password combination and grant access if they do.

Authentication is full of security issues. If you are not familiar with authentication you might be better off using one of the authentication libraries in the Wiki.