How to have a view that displays the front camera view or a black screen if its an iphone 2g/3g/3gs? I need a view that it's like a mirror?

There开发者_高级运维 is a way to do that? Thank you very much for your time I need only the view from the front camera or a black screen if its an iphone 2g/3g/3gs...

[UIImagePickerController isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceFront]

Should return true if there is a front camera, false if not. I've never had the opportunity to test this function on a phone with a front camera though.