//I think this is right

var message = [[UIAlertView alloc] init];
message.title = "Dialog title here";
message.message = "Main message here";
[message addButtonWithTitle:@"Close text here"];

//For the effect, make sure your iPhone's unlocked
[message show]; //You can run this over and over to show the same dialog box

/* You can change the text any time you want (except for the button) by
running message.title or message.message again */