Firstly, there is no explicit JSON support in Designer and I am no JSON
expert and I do not know anyone who has done this but logically speaking
you woudl have to get the JSON message into the form some how. Maybe
pass it in a SOAP call as a string. Then once it is in the form you
coudl use Javascript to manipulate the message and populate the DDList
the way you want.Hope that helpsPaul