Misc Workflow Extensions - Copy Value from field to field (condition not working)

Susan Hauth _Jira Queen_

We are using post workflow function to copy the "reporter" to a custom field. Without a conditional execution it works fine. But I want it to execute only if the custom field is not filled in (null). I have tried every type of groovy expression and cannot get it to work. Sometimes I get an error on the syntax, but when I don't get an error, it simply ignores. What is the proper syntax for verifying if a custom field (user picker) is null in the conditional execution?

I've tried cfValues['name of the custom field'] == null. But to no avail. Help!

David _old account_

The condition should be something like:

issue.get("customfield_10070")==null

where "customfield_10070" is the ID of the custom field (you can find the actual number by looking at the Edit custom field link in the admin)