cannot launch iPhone camera

I want to use iPhone camera in my application and followed the steps as suggested in the forum. I use texture of a plane or cube to show the camera picture. It works fine when I test it on Mac with Unity3d. But when I build an iOS version and run on an iPhone, it is not able to launch camera. As soon as application is launched it is giving a pop up saying do u want to allow device cam…on clicking ok the popup disappeared but cam is not launched.
Thanks in advance!

Consider using NatCam.