Click the box tool to create a box, by clicking on an empty space in the board.
To move a non selected box, click the box and keep the mouse down while moving it. The connected lines will follow. A selected box cannot be moved.
Click the box to select it. Click again to deselect it. If there are several selected boxes, you may deselect them all by clicking on an empty space in the board.
If you want to create several boxes, double-click the box tool to stay on. To return to the select mode double-click the select tool.
Click the line tool to create a line between the last two clicked boxes, by clicking on an empty space in the board.
If you want to create several lines, double-click the line tool to stay on. To return to the select mode double-click the select tool.