I need a record locking routine, if anyone could give me...

Here's the setup... Inventory system with table : Tbl_Product_Inv_Count, there is a field name: QTY_FOR_SALE.

What i want to do is lock the current record from other users until im finished updating the field QTY_FOR_SALE. (is it possible???)

I've tried other locking routines found in this forum, but to no avail... will somebody enlighten me on this....

How do i lock it??? How to detect if the record is locked ???
How do i test it??? will i test it on a single PC ???


Help gurus!!! TIA...
(Im using VB/ADO/SQL)