screen lock button to ending call

Hi all! I'd to give all of you tips about a very practise tips. I have iPhone 5 with Ios 7.0.4 and VO. When I will end a call, tap once on screen lock button on top of the phone when you hold next to ear. You don't need to double tap with two fingers. This way is great, faster and when you had tapped once then the phone also locked itself. Before you could do this by double tapping on the screen lock button but now only that once. :)