Cells can be edited by either typing directly into them or by selecting a cell and editing the contents of the cell edit box above the grid. To edit a cell directly simply start typing when the cell is selected. The contents of the cell will be replaced with what you type. To directly edit a cell without overwriting all its contents double click on the cell; this will switch the cell into edit mode. To leave edit mode simply press escape or navigate to another cell, using the mouse, arrow keys, or TAB. The F2 function key can also be used to toggle a cell between edit modes.