LimitSelect

Private Sub Check1_Click(Index As Integer)
Dim chk As CheckBox
Dim lCnt As Long
Const cMAX = 3
For Each chk In Check1
If chk.Value = vbChecked Then
lCnt = lCnt + 1
If lCnt > cMAX Then
Check1(Index).Value = vbUnchecked
MsgBox "Too many checked!"
Exit For
End If
End If
Next chk
End Sub