How to change UIAlertView cancel button text

I would like to开发者_如何学Python know that how to change UIAlert's cancel button text during runtime.

- (void)showAlertWithTitle:(NSString*)title message:(NSString*)message cancelButtonTitle:(NSString*)cancelTitle {
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:title message:message delegate:self cancelButtonTitle:cancelTitle otherButtonTitles:nil];
    [alertView show]
    [alertView release];
}