The name of the field in the listname working list that contains the name of the WAM whose Webroutine is to be invoked when a tree item is selected. This is only valid for unlevelled lists and will be ignored if listtype is "levelled".
Blank. The WAM specified by onselect_wamname will used.
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.