[rules-users] Event wait constraint syntax

I am trying to figure out how to specify the constraint for Event wait. The rules flow diagram attached would be launched for each incoming "request". The request is set in a process scope variable (reqIn). Each request has a *tag* associated with it. The event wait in question is waiting for a response event with the same tag value. How would I create a constraint rule to match this? I guess the bigger question here is, how do I access the process scope request variable in the constraint? Something like: RFQResponse (tag == reqIn.tag) PS: When I try this, I get an error: "Unable to create restriction '[QualifiedIndentifierRestr: == reqIn.tag ]' for field 'tag' in the rule 'RuleFlow-Milestone-com.rbs.gbm.pm.RFQ-WorkFlow-21' : [Rule name='RuleFlow-Milestone-com.rbs.gbm.pm.RFQ-WorkFlow-21']" Any help / pointers would be highly appreciated. Thanks Ajay Gautam *****Please note that my email address may have changed. For all future correspondence, please use this address***** ********************************************************************This message (including any attachments) is confidential and/or privileged. It is to be used by the intended recipients only. If you have received it by mistake please notify the sender by return e-mail and delete this message from your system. Any unauthorized use or dissemination of this message in whole or in part is strictly prohibited. Please note that e-mails are inherently insecure and susceptible to change. The Royal Bank of Scotland Group, plc ("RBS") and its US subsidiaries, and affiliates and subsidiary undertakings, including but not limited to, RBS plc New York and Connecticut Branches, RBS Securities Inc., ABN AMRO Bank N.V. New York and Chicago Branches and, ABN AMRO Incorporated, Citizens Financial Group, Inc. and RBS Citizens, N.A., shall not be liable for the improper or incomplete transmission of the information contained in this communication or Attachment nor for any delay in its receipt or damage to your system. RBS does not guarantee that the integrity of this communication has been maintained nor that this communication is free of viruses, interceptions or interference. RBS and its subsidiaries and affiliates do not guarantee the accuracy of any email or attachment, that an email will be received or that RBS or its affiliates and subsidiaries will respond to an email. RBS makes no representations that any information contained in this message (including any attachments) are appropriate for use in all locations or that transactions, securities, products, instruments or services discussed herein are available or appropriate for sale or use in all jurisdictions, or by all investors or counterparties. Those who utilize this information do so on their own initiative and are responsible for compliance with applicable local laws or regulations.********************************************************************