Thread: If formula that has to look at two cells to see if they are blank

I am trying to to a formula with the the following formula in cell x157 =IF(G157-(S103-O157)<0,"YES","NO") this part works but my problem is that I need to add on to it so that the formula needs to look at cell G157 AND/OR cell O157 and if both of them are blank it will come back with "NA" but if only one cell is blank it will look at the cell with the value to come back with YES or NO. Can you help with this? Thanks so much!