VLOOKUP formula for stock control

Hi all,
I am working on a formula for a stock control spreadsheet. I am trying IF VLOOKUP but it is not working.
I would need a formula in column "product in stock' in components lot register spreadsheet that would say 'NOT AVAILABLE' when for example:
Lot number '100' (D4) for product 'procedure pack' (C4) for 'component 1' (B4) appears in the spreadsheet 'Lot Register' (A:W), and 'AVAILABLE' when 'lot number' does not appear in "lot spreadsheet" and 'released' column in the spreadsheet "components lot register' says YES.

Thanks!!