The name of the field in the listname working list that contains the name of the Webroutine in the current WAM that is to be invoked when a tree item is selected.
Blank. A Webroutine will not be invoked when a tree item is selected.
The name of a valid field, in single quotes. A list of fields in the listname working list can be chosen from by clicking the corresponding dropdown button in the property sheet.