Set objWMI = GetObject("winmgmts://./root/MOM")
strQuery = "select * from MSFT_Alert where ResolutionState <> 255"
Set colAlerts = objWMI.ExecQuery(strQuery)
  
For Each objAlert In colAlerts
   If Len(Trim(objAlert.AlertHistoryComment)) = 0 Then objAlert.AlertHistoryComment = Null
   If Len(Trim(objAlert.CustomField1)) = 0 Then objAlert.CustomField1 = Null
   If Len(Trim(objAlert.CustomField2)) = 0 Then objAlert.CustomField2 = Null
   If Len(Trim(objAlert.CustomField3)) = 0 Then objAlert.CustomField3 = Null
   If Len(Trim(objAlert.CustomField4)) = 0 Then objAlert.CustomField4 = Null
   If Len(Trim(objAlert.CustomField5)) = 0 Then objAlert.CustomField5 = Null
   If Len(Trim(objAlert.Description)) = 0 Then objAlert.Description = Null
   If Len(Trim(objAlert.OwnerName)) = 0 Then objAlert.OwnerName = Null
   If Len(Trim(objAlert.ResolvedBy)) = 0 Then objAlert.ResolvedBy = Null
   If Len(Trim(objAlert.TimeResolved)) = 0 Then objAlert.TimeResolved = Null

   objAlert.ResolutionState = 255
   objAlert.Put_
Next