Selecting from a combo box after initial parameter entry.

[BigAl]

This is probably very easy but I'm stuck.

I want to open a form which prompts for a customer code. The sql for the
underlying form query is:

SELECT tableHD_Lot_Desc.[Customer Code], tableHD_Lot_Desc.HD_Lot_No,
tableHD_Lot_Desc.Material
FROM tableHD_Lot_Desc
WHERE (((tableHD_Lot_Desc.[Customer Code])=[Enter Customer Code]));


What I want after this is the ability from a combo-box to select the
relevant HD_Lot_No and display that along with the material. The query works
fine selecting only the HD_Lot_No's relvant to the input Customer Code but
my combo box on the form always displays all HD_Lot_No's for every Customer
Code. As there will be an associated sub-form with this I can only this main
form display as a single form.

I'm obviously doing something wrong and I'd be very grateful if someone
could point out what.

Cheers

BigAl