A user can choose a color using radio buttons to draw lines. Until the color is changed, any line will be drawn with that color. The default color is black. A user can move a mouse in the drawing panel and press the mouse where he/she wants to start drawing a line. The first point that a user clicks will be the starting point of the line. After a user presses the mouse, a user should "drag" the mouse until the mouse reaches to a point to determine the ending point of the line.