%INCLUDE "lsconst.lss"  ' for MB_xxx constants

Sub Click(Source As Button)
 Dim ws As NotesUIWorkspace
 Dim uid As NotesUIDocument
 Dim uis As NotesUIScheduler
 Set ws = New NotesUIWorkspace
 Set uid = ws.CurrentDocument
 Set uis = uid.GetSchedulerObject("Main")
 If Messagebox("Do you want to change this setting?", _
 MB_YESNO + MB_QUESTION, _
 "DisplayCheckboxes is " + _
 uis.DisplayCheckboxes) = IDYES Then
   uis.DisplayCheckboxes = NOT uis.DisplayCheckboxes
 End If
End Sub

Glossary