Select your range of cells in column A. Edit / Go to / Special / Blanks.
Type = and then press up arrow. Then hit Shift Enter.
If you are happy with this result, select the range again and Edit / Copy
then Edit / Paste Special / Values to fix the values in place.
1.select the column A.
2.Press F5 key
3.select special button-->Then select Blanks.
4.Some cells will be selcted,now just type = & select the upper cell
do ctrl+enter.
Experts,
Any correction in this..........pls help.