Show summary of a field
I have two tables: A and B. I created a layout based on table B. I have a field a1 on table A and I want to put the sum of this field a1 as a total number into the layout. The two tables have a relationship by ID number. How should I do it? I tried to create a summary field of a1 from table A and use field picker to add to the layout, but seems not working. Can anyone help pls? Urgent!