You can use the scroll bars in the Map window to move the map up, down, right, or left. If the scrollbars have not been turned on as the default (on the Optionsscreen, click Map Window), then you can turn them on for the window you are working in.
To show the scroll bars on a per-window basis:
Note: Sometimes you may scroll so far that you move your view completely off the map. When this happens, the map appears to be blank. Simply activate Previous View or View Entire Layer by right-clicking on the map. Either of these will return you to your previous view of the map, and you can reposition the map again.