Thanks Cetin,

The Client_number from the Combobox(Allocation_Numbers.Client_Number) must also be copied to a textbox(F_Accounts.Client_Number) on the form. This number is always 4 characters long ie 1006. The Client field(Allocation_Numbers.Client) goes to the Controlsource(F_Accounts.Client) Sorry if I did not express it to well in the -A- part.

As for the interactivechange:

The form is related to table F_Accounts. The Depot_Number is always 6 characters long ie 732977. Thus the value for Exp_Alloc_Number will be 1006732977. If I understand it correctly then the second padl will become

padl(F_Accounts.Depot_Number,6,"0") and the first padl will become

padl(F_Accounts.Client,4,"0")

If, when the client in the Combobox is selected ie "Data Processing" and its corresponding Client_Number is written to the Client_Number on the form, would it not be easier to say in the interactivechange

thisform.Exp_Alloc_Number.textbox.value = ;
thisform.Client + thisform.Depot_Number

or is this DOS type concatenation not on.

Petrus.