VLOOKU

I have 2 sheets, sheet 2 has Part description and Part Number in 2 columns.

Part 1                     Part No 1

Part 2                     Part No 2

Part 3                     Part No 3

Part 4                     Part No 4

Sheet 1 I have used Data Validation to bring in Part 1, Part 2, Part 3 or Part 4.

Now in Column 2, I want to bring in the Part No that corresponds to Part item.

If I have the information all on 1 sheet, I can use VLOOKUP to bring in the info I want. How can I do it to bring the Part No in from Sheet 2?

I hope I have not confused you too much.

Thanks

Bryan