The two scrollbars on the left and bottom of the Display window control the position of the small window relative to the large window. By manipulating the scrollbars you can control the location of the inner window over the large window that contains the network. The left scrollbar controls the vertical position of the inner window while the bottom scrollbar controls its horizontal position. The current location for the inner window is indicated by the position of the white square on the grey strip in the middle of the scrollbar. The grey area represents the height and width of the outer window while the white square indicates where the inner window currently lies within this area. Note that the size of the white square does not reflect the relative size of the inner window to the outer.