To copy a part, do the following:
As you move the mouse, you see an outline of the part you are copying, and a border around the window or form that will contain the new part when you release the mouse button.
If the part you are dragging is one of several parts that are selected, all of the selected parts are copied.
If you start to copy a part and then decide you do not want to, press Esc before releasing the mouse button.