Hi
Many thanks for that, but the only way I can get that to work if I reduce the arguments ie =IF(ISBLANK(B2),IF(A1>0,),A1+1)
Then it produces errors in Col A which I have formated to ignore and then with conditional formatting to blank out the 0 and the FALSE which it gives in alternative cells in the column.
It works but I don't like ignoring errors.

Many thanks
Bern