camera problem in iphone sdk

i would like to open camera in my tab bar app.. i have open the camera but i could not taken the picture because i didnt find the camera symbol in that screen so please tell me how i can i show the camera button(for capture) in camera view? i am also tested it in my iPhone. camera opened but i could not find any button to pick the image..开发者_JS百科 how can i got if? Thank You.. code is

picker = [[UIImagePickerController alloc] init];

picker.delegate = self;

picker.sourceType = UIImagePickerControllerSourceTypeCamera;

[Delegate presentModalViewController:picker animated:YES];

use

       [self presentModalViewController:picker animated:YES];

instead of

  [Delegate presentModalViewController:picker animated:YES];