Hi All,
first i should thanks to men who share their expertise earlier.
this time again i am looking for a logical formula for to calculate simple
addition in the fifth column with the condition that it should satisfy in all
previos columns (off course not for the first one)

A B C D E
1 + 2 + 3 + 4 = 10
--- + 2 + 3 + 4 = ----- (should leave blank)
1 + ---- + 3 + 4 = ----- (should leave
blank)

and so on.. until D

Ultimatly it should add up if there are a desired values in all previous
cells (some thing like a combination of double if & and