IPhone : How to present a modal view controller force in scape type?

I am using code as below, but it doesn't work.

   - (BOOL)shouldAutorotate
{
    return YES;
}

- (NSUInteger)supportedInterfaceOrientations
{
    return UIInterfaceOrientationLandscapeRight;
}

-(UIInterfaceOrientation)preferredInterfaceOrientationForPresentation
{
    return UIInterfaceOrientationLandscapeRight;
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    //return YES;
    return UIInterfaceOrientationLandscapeRight;
}

I don't know why it does not work.