Summing One field for Default Value of another

[valley]

I have two Numeric fields in my Table, MCRefill and MCTot.
Actually MCtot is the sum of all MCRefill for a given Cust_ID

I have the following expression in the Default value of MCtot in my form showing both the fields

DSum("[MCRef]","Miracle_Cloth_Main","[Cust_ID]='" & [Cust_ID] & "'")

Somehow it doesn't up in the record when you load the Last record for a Cust_ID

Can someone please help ?

 

[MStef]

Hello Valley!

You don't need to save MCTot in tbl, because you can calculati it
always you need it.
Look at "DemoMCtotA2000.mdb"

 

[valley]

Hello Mstef

Many thanks for your reply and example.
I have looked at the example.
What I am trying to do is for a PDA application where
the info is required (when a customer is revisited)
on a form field (without having to open and look at the table)
To keep it simple I try to use only one table and one form
I have
=DSum("[MCRef]","Miracle_Cloth_Main","Cust_ID ='" & [Me].[Cust_ID] & "'")
as the default value for the MCRtot field.
I have values in several records for MCRef but it doesn't appear in the form though it looks like the formula is there as it comes up with#NAME? in New records

Could you please help ?