If you need to know if the move you've got in mind is valid, you can pop-up a window that shows all valid moves for the given position. Choose this item from the Moves menu.

 

Next you can use the mouse or the keyboard to select a move from the list that than will be executed on the board. You do not need to type it in again or move the desired piece. Enter or a double-click issues the move. Escape closes the window.