understanding excel for access purposes

[metokushika]

hi. i need to make a form in access related to the records from excel. i need the operations to be exactly the same from excel so i could convert the calculations in ms access. but i don't know what this means? =(IF(ISNA(VLOOKUP(G12,$AI$9:$AJ$10, 2, 0)),0,VLOOKUP(G12,$AI$9:$AJ$10, 2, 0))) it's from one of the calculations in excel. i just want to understand what the logic is about. any help would do! thanks!

[pbaldy]

If the value from this lookup is NA, return a 0, otherwise return the value from the lookup.