I am trying to score results
- M4 = test criteria (e.g. 5)
- O4 = test result (blank or a number .001 to 9999)
- P4 = scoring (if the result is blank, retun a blank in P4. if result is
less than test criteria set P4 to 100, else 0)

I need to check for blank and return a blank so that when I total the
scores, I'm not averaging in a zero.

I need to replace this which returns a 0 when O4 is blank:
=IF(O4="",0,IF(O4<=M4,100,0))
This returns an error for using the "" replacing the 0:
=IF(O4="","",IF(O4<=M4,100,0))

Ideas?