The value of the On Field Update Set user property consists of three quoted parameters separated by a comma and a space, as follows:
"FieldToCheck", "FieldToSet", ["Value"]
where Value is an optional parameter.
FieldToSet is set to Value when FieldToCheck is updated. If the Value parameter is not defined, FieldToSet is set to the value of FieldToCheck.
An expression can optionally be used for the Value parameter. In the following example, the Done field is set using the expression when the Done Flag field is updated.
"Done Flag", "Done", "IIF ([Done Flag] = "Y", Today (), "")"
Additionally, if you use an expression, you can include a fourth parameter that defines a condition.
NOTE: If you use an expression, it must evaluate to the data type of the targeted field. In the following example, the ToChar function is used to convert the date to a string before concatenating with another string and setting value of the field.
"Agreement Start Date", "Name", "ToChar([Agreement Start Date]) + [Agreement Type]"