Creating a DFF with a reference field

Hi

I am trying to create a DFF in the requisition form. I want to show to the user different segments according to the value of the field "Type" in the requisition form.

To achieve this, I did the following

1. In the flexfield segment form, I choose the field "TYPE_LOOKUP_CODE" as my reference field (in fact it appeared as a LOV)

2. Displayed check box in un-marked 

3. In the context field values section, I have defined the 2 values which are permissible for the context field. I have tried 2 sets of values (INTERNAL, PURCHASING and Internal Requisition, Purchasing Requisition)

The result is negative. The flexfield pop up window does not show at all