I really don't know how to ask this in a single sentence so here is the situation:

I have a database that has record about an item inventory. Based on the database's primary key which is item_no. If I have 10 records of Items in my database, then item_no should have the last element "10" in the column item_no. The problem is, I want to post in a textbox automatically the next item_no value which is "11". Can someone reply an answer in this thread? thanks!