Hi Kirk
You can set the enabled property for all but the active page to .f. when editing or adding and reset Enabled to .t. when not editing.

*!*if in edit mode
with thisform.pageframe1
for m.lnI = 1 to .pagecount
  if  .ACTIVEPAGE = m.lnI
     *** set  enabled .t.
     .PAGES(m.lnI).ENABLED = .T.
  ELSE
    .PAGES(m.lnI).ENABLED = .F.
  endif
next
endwith

*!*if not in edit mode
with thisform.pageframe1
for m.lnI  = 1 to .pagecount
    .PAGES(m.lnI).ENABLED = .T.
next
endwith

HTH
Elmer