Vlookup

[Mikeeverest]

I have a formula that is working but needs slight modification to it and I cant seem to get it straight
Right now my formula is:
IF (ISBLANK(AR2) = TRUE, "", VLOOKUP(AR2, Reference!$c$17:$d$19,2))

I need to find out if AR2 is blank and/or AS2 then leave it blank, if not then I need to lookup the SUM of AR2+AS2

I tinkered around but its not working
IF (ISBLANK(AR2,AS2) = TRUE, "", VLOOKUP(SUM(AR2,AS2), Reference! ..)

Thanks

 

[Mikeeverest]

think i got it

IF (OR(ISBLANK(AR2),ISBLANK(AS2))=TRUE,"", VLOOKUP(SUM(AR2,AS2),Ref...