MI-L Dialog - Checkbox handler doesn't work

[Terry McDonnell]

Dear List
 
In the code below, when entering the dialog, or when clicking the
"Display &All Routes" checkbox the handler ENABLE_STOPS_TOO is invoked
and, to my mind, should enable or disable the "Display &Stops Too"
checkbox, depending on glAllRoutes.
 
But, of course it doesn't.  Can anyone tell me why, please?
 
Sub DISPLAY_ROUTE_DIALOG
  Call GET_PLOTTED_ROUTES
  DIALOG
   Title "Display or Hide Routes"
   Calling ENABLE_STOPS_TOO
  Control CheckBox 
       Title "Display &All Routes"
       Calling ENABLE_STOPS_TOO
       Value glAllRoutes 
       Into  glAllRoutes
  Control CheckBox 
       ID STOPS_TOO_BUTTON_ID
       Title "Display &Stops Too"
       Value FALSE 
       Into  glStopsToo
   Control StaticText
       Title "Select a Route to display from List:"
   Control PopUpMenu 
       Title from Variable gaRouteNames 
       Value 1
       Into  gnSelID
   Control CheckBox 
       Title "&Hide All Routes"
       Value glHideRoutes
       Into  glHideRoutes
   Control OKButton
   Control CancelButton
 
   If CommandInfo(CMD_INFO_DLG_OK) Then
       Set map redraw off
       Call REMOVE_PLOT_HILITE                    ' Disappear any
highlighted zones-plotted route layer
       Call REMOVE_STOPS_HILITE                 ' Disappear any
highlighted Route's Stops layer
       Call DISPLAY_WHAT_ROUTES
       Set map redraw off
   End If 
End Sub
 
'________________________________________________
Sub ENABLE_STOPS_TOO
  If glAllRoutes then
       Alter Button ID STOPS_TOO_BUTTON_ID Disable      ' Disable Stops
Stops Too button of Display route Dialog
  Else
       Alter Button ID STOPS_TOO_BUTTON_ID Enable       ' Enable Stops
Too button of of Display route Dialog
  End if
End Sub
 
 
TIA
 
Terry