How Can I enable dependent Value set ?

Hi ,

If I have to 2 fields in a request and each one has its flex value set.

The Second field's value_set to retrieve its data as the value of the first one.

Till now every thing is OK

but what I want is if the first one is null I Found the second one is dimmed , I cant insert data into it till the first field is populated

Any suggestion ?

Pls find attached Screen shot for more clarification

the code I used in flex field is

WHERE ORGANIZATION_ID = :$FLEX$.P_ORG_ID

AND (SEGMENT2 = :$FLEX$.P_FAMILY OR :$FLEX$.P_FAMILY IS NULL)