PR Workflow(Overall Release) - Workflow not Triggering for Refusal

Hi,

I have a client requirement in which I have to set work flow in which if the approver of Purchase Request is refusing release, the creator should get a mail.

I have done configurations for other process like

1. Mail if PR created

2. Mail if PR Released.

Work flow is triggered for those process, but for the Refusal alone, I am unable to get the mail.

I doubt if I am missing anything. Please help.

Thanks,

S.Raghavan