Message box based on user entry in cell

Greetings, Gurus.

I'm trying to create a macro to automatically run when a user types anything in cell B39. The macro would search the value of the entry, and would perform a lookup against a table named "recnwpp". If the value is found in the table, I want a message box to pop-up saying "This Part # should end with R". The user should have to click Okay. If the entry is not found, then the macro should simply exit. I don't want the macro to run if the cell is changed from a part number back to an empty cell.

I don't know how to perform a vlookup in a macro, and I don't know how to assign a macro to a cell change event. Any help would be greatly appreciated.

Thanks, Noob. I'll check it out.

Have a good one!