6. The system of claim 5 , wherein the detecting comprises detecting a forward movement of the object, wherein the forward movement is movement along a z-axis toward the display, wherein the z-axis is defined as an axis normal to a front region of the display.
7. The system of claim 6 , wherein the detecting comprises detecting a rearward movement of the object, wherein the rearward movement is movement along the z-axis away from front region of the display.