this works. In my report it generates a total for all records in the table ADMIN_TTOUR where the CUSTOMER_ID =1

=DSum("[QUANT_CARGO]";"[ADMIN_TTOUR]";"[CUSTOMER_ID]='2'")

But, I don't need that! I want to use a query as the source and NOT a table. The query is named DAG_TONNEN and according the help file of MS Access the domain can either be a table or a query. However, I get the message ERROR displayed in the report. I assume the sytax is ok, but am overlooking something here??

This doesn't work!

=DSum("[QUANT_CARGO]";"[DAG_TONNEN]";"[CUSTOMER_ID]='2'")