The Columns button enables the user to choose the number of columns of hosts displayed on the Tree View canvas frame from a list of preselected numbers. When the user clicks on this button, a pull-down list of radio buttons is displayed. The user can then select the desired number from a list consisting of 2, 3, 4, 6, 4, 8, 10, 15, and 20 columns. Note that the size of the circles and rectangles changes in response to the choice while the size of the canvas remains constant.