Email Validation in iphone

  NSString *emailString = textField.text;
 
    NSString *emailReg = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";
    NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",emailReg];
    if (([emailTest evaluateWithObject:emailString] != YES) || [emailString isEqualToString:@""])
    {
        UIAlertView *loginalert = [[UIAlertView alloc] initWithTitle:@" Enter Email in" message:@"abc@example.com format" delegate:self
                                                   cancelButtonTitle:@"OK" otherButtonTitles:nil];
     
        [loginalert show];
    }