How to get data to appear automatically from another table

[Ant@20]

I want cost data from the other delivery table to come automatically to appear in this order table as soon as I click Pick-up or any other delivery option from the drop down box. This is necessary because if I was to only have 2 drop downs then I could click £10 accidentally for pick up which is £0 or any other similar mistakes. Please help quickly, this is urgent.

[ssanfu]

I don't think this can be done if you are entering data directly into a table.

Now if you were using forms, that is a different matter.
In the delivery table, I would have three fields: "DeliveryID" (autonumber), "DeliveryOption" (Text) and "DeliveryCost" (Currency).
The row source for the combo box would something like:

SELECT DeliveryID, DeliveryOption, DeliveryCost FROM DeliveryTable ORDER BY DeliveryOption

The bound column would be 1
the Column count would be 3
the column widths would be 0, 1.3, 0

There would be code in the after update event of the combo box that would push the delivery cost into the delivery cost control:

Sub cboDeliveryOption_Afterupdate()
    me.DeliveryCost = me.cboDeliveryOption.Column(2)  '(columns property is zero based)
End Sub

Or you could write a UDF to get the delivery option cost.
In the delivery option combo box after update event, set the delivery cost control to the return value of the UDF.