[iphone] 경고창 띄우는 법

   UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"login" message:@"메세지" delegate:self cancelButtonTitle:@"확인" otherButtonTitles:@"취소", nil];

[alert show];

[alert release];

참고 : http://blowmj.tistory.com/entry/IPhoneUIAlertView경고창-띄우는-방법과-경고창이-여러개일-때-이벤트-구별하는-방법