QueryException in Connection.php line 647: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'saini' for key 'users_email_unique'

Hello Friends, I have a simple register form where users fill their put firstname/lastname/email/password but whenever i fill same first/last name my site throws above error. However first/last name are not uniques..

Here is my controller..

    $rules = array('firstname'=>'required|alpha','lastname'=>'required|alpha','email'=>'required|email|unique:users','password'=>'required');

    $customMessage = array('firstname'=>'First Name is required','lastname'=>'Last Name is required','email'=>'Email is required','password'=>'Password is required');

    $data = Input::except(array('_token'));
    $validator = Validator::make($data,$rules,$customMessage);

    if($validator->fails()){
        return Redirect::to('register')
                ->withErrors($validator);
    }else{

        HomeModel::saveFormData($data);
        return Redirect::to('login')
                ->withMessage('Data Inserted');
    }