Drop down bars?

[hutchijw]

After I enter information into a row (company name, P.O., items, dollar amount, if it's been invoiced, if it's been shipped...and so on), I want to be able to put a drop down arrow into the P.O. field so each company only has 1 row. Then, after receiving another PO, use the drop down bar to add/edit each of the fields following the PO field. Is this possible?

Thanks in advance,

Hutch