Sets or retrieves the value-on-error for the currently selected page association.
ValOnErr = PageAssociationValueOnError
Value to be used if the substitution was not performed and a default value was not defined, or a tag name was specified that did not resolve.
The value-on-error for the currently selected association (as a string), or 0 (zero) if successfully used to set the value-on-error. An error is returned if unsuccessful.