StartDrag command for 1 axis only

This tutorial details how to have an object follow the mouse on 1 axis only (not possible with the drag command). This gives the effect of it sliding across the screen. This can be done easily by making the x/y position of the object equal to the corresponding position of the mouse. However, to make the movement look more authentic, like it is following the mouse, not just always in the same position, you can add a small piece of code which makes it lag behind a little.