iOS - dismiss keyboard when touch on background

gistfile1.txt

 //--Touch to dismiss keyboard
		UIButton *dismissKeyboardButtonBg = [UIButton buttonWithType:UIButtonTypeCustom];
		dismissKeyboardButtonBg.backgroundColor = [UIColor clearColor];
		[dismissKeyboardButtonBg addTarget:self action:@selector(dismissKeyboard:) forControlEvents:UIControlEventTouchUpInside];
		[dismissKeyboardButtonBg setFrame:CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height)];
		[dismissKeyboardButtonBg setAutoresizingMask:UIViewAutoresizingFlexibleWidth];
		[self.view addSubview:dismissKeyboardButtonBg];