Sum of a queryfield in a formfield

[quacka]

Hopefully a very simple question for you guys, but I don't know how to start.

I have a query (let's call it Query1)
3 fields: ID, Date and Amount.

In a form I want a field with the sum of Amount, for a choosen ID. (this choosen ID is already somewhere in the form: Textfield 'FormID').
Let call this field 'SumAmount'

ID - Date - Amount
A - 5/10/2008 - 50
A - 5/11/2008 - 60
B - 5/12/2008 - 40
(in reality 10-15 ID's with already 5000 records and increasing...)

When FormID = A, I want 'SumAmount' to be 110.
When FormID = B, I want 'SumAmount' to be 40.

I need to open the query as a recordset. But I don't know how to do it exactly.
Maybe someone can help me!

 

[Rabbie]

Just use this
dsum("Amount","Query1","ID='FormID'")

 

[quacka]

Just use this
dsum("Amount","Query1","ID='FormID'")

So simple

But thanks a lot: It works great.

 

[Rabbie]

So simple

But thanks a lot: It works great.

Happy to have been of help. All questions are easy when you know the answer