UIButton click event crash after adding the viewcontroller's view as a sub view

I want to add several ViewController's views as sub views of my another viewcontroller. So I have done like this inside my parent viewController.

-(void)MakeDisplayArea
{
vwDisplayArea=[[UIView alloc] initWithFrame:CGRectMake(0, 0, w, h-scrolTab.frame.size.height)];

[self.view addSubview:vwDisplayArea];
}





-(void)ProfClick :(id)sender

{

    [self MakeDisplayArea];
    ProfileViewController *profviewcontroller=[[ProfileViewController alloc] initWithNibName:@"ProfileViewController" bundle:nil];
    profviewcontroller.view.frame=vwDisplayArea.frame;
    [profviewcontroller.view setBackgroundColor:[UIColor clearColor]];
    [vwDisplayArea addSubview:profviewcontroller.view];

}

Then inside the profViewcontroller ViewDidLoad methods I am generating a button and set the target like this.

UIButton *btn=[[UIButton alloc] initWithFrame:CGRectMake(10, 60, 100, 30)];
[btn setTitle:@"Button Test" forState:UIControlStateNormal];
[self.view addSubview:btn];
[btn addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];

-(IBAction)btnClick :(id)sender
   {

      NSLog(@"button clicked-------");
   }

I can see the button is appearing on that profViewcontroller that I loaded as a sub view, but when I click the button the app is crashing. What is the correct way add that viewcontroller as a subview on my first viewcontroller. Please help me.

Thanks

via Chebli Mohamed