Microsoft Access If statement

I was wondering if you can make a if statement in Microsoft Access. The idea is you have 2 columns. 1st one is called "Quantity"(type is number) and 2nd one is called "In stock" (type Yes/No) and want to make statement if quantity > 0 then "In stock" should be tick otherwise no tick. I was trying "iff([quantity] = 0, [in stock] = "No", [in stock] = "Yes")

also tried this

"iff([quantity] = 0, [in stock] = false, [in stock] = true)

Hopefully you get it, can someone help or tell me if its possible to make this? Thanks in advance