Woek flow for PO change Event

Hi,

I'm developing WF for PO change event based on Purch doc type = NB.

I have provided the start events and created WFcontainer elements and generated the bindings for the same.

Noe the problem is, i have to specify the start condition as Purch doc Type = NB.

when i click on the conditions button i'm not getting the Purch doc type parameter.

has any one come across this problem.

Regards,

Raghavendra