Checkbox in an If statement

Upon saving, I'm trying to show a messagebox when none of the 4 checkboxes in
the document are checked and to cancel saving.

I'm using checkboxes from the control toolbox.

It's giving me an error on the If statement called: Run-time error '424".
Object required.

This is the code that I'm using:

Sub FileSaveAll()
If ChkboxTMS1.Value = False And ChkboxTMS2.Value = False And
ChkboxTMS3.Value = False And ChkboxTMS4.Value = False Then
MsgBox "Please select a radiobutton and retype your changes."
Exit Sub
Else Documents.Save
End If
End Sub

Any thoughts?

Thank you