Problem with sorting on a Sub-Summary layout part
I have a layout named "Invoice Preview" which includes a Sub-summary part sorted by a text field named "Description" in a table named "Line Items". This layout is used only in Preview mode for printing purposes. There is another layout named "Invoice Detail" on which the line items are entered in a portal.
I want to control sorting of each line item on the "Invoice Preview" layout by other than the "Description" field, so I have added a number field named "Line_Item_Order_Number" in the "Line Items" table, added it to the portal in the "Invoice Detail" layout, and tried setting sorting in the sub-summary part on the "Invoice Preview" layout by the "Line_Item_Order_Number" field, but it does not work.
Both fields are included on the "Invoice Preview" layout, within the Sub-summary part. When I change the sort field to "Line_Item_Order_Number", the Sub-summary does not function; in fact the "Line_Item_Order_Number" field does not even show up in the layout, though it does show up when I change sorting back to "Description". Any ideas why?