I have 3 Checkboxes each with its own procedures, that is linked to a command button, like below, but when you select any combination of the boxes a Msgbox: must pop up saying please select only 1 checkboxs at a time.
How do i do that?

Private Sub CommandButton6_Click()
If CheckBox1 = True And CheckBox2 = False And CheckBox4 = False Then
Sheet14.Activate
Unload UserForm1
Else
End If

If CheckBox2 = True And CheckBox1 = False And CheckBox4 = False Then
Sheet6.Activate
Unload UserForm1
Else
End If

If CheckBox4 = True And CheckBox1 = False And CheckBox2 = False Then
Sheet1.Activate
Call RunProgramSequence1
Else
End If

End Sub

'MsgBox "Please make only one 'Planning' selection" & Err.Description, vbExclamation, "AI-Program: Power Utility Pack 2006"