With the button shown above or the menu Input > Lines the lines-window is opened. By clicking the button >> a list of line codes is opened.
To draw a line between two points choose the radio button New and click on the start and end point of the line. To remove a line activate the radio button Delete and double-click the respective line. If the Auto checkbox is activated the mouse arrow catches the nearest point. With the Change radio button the code of the line can be changed.