How to set "current.assigned_to" to a null value whenever the condition "current.assignment_group.changes()" is met?

[wei2]

We have implemented a business rule to set "current.assigned_to = 0" whenever the condition "current.assignment_group.changes()" is met.

However, this caused the following issue:
When the incident is moved to "resolved" status, "current.assigned_to = 0" is still accepted, while the business process requires that the "current.assigned_to" field must be populated with the correct user name.

Therefore, we want to find out if there is a way to force the "current.assigned_to" field to NOT accept the "0" value when the incident is moved to "resolved" status.

Thanks,
Will

[wei2]

http://wiki.servicenow.com/index.php?title=Setting_a_GlideRecord_Variable_to_Null

[wei2]

current.assigned_to = 'NULL';
current.update();

[Mark Stanger]

How about current.assigned_to = ''.