simple checkbox questions

I have two check boxes; If I click on the first the box is checked, if I click on the second, I want the first box to uncheck and the second to be checked. I thought this code would do the job, but it's working like I want. What do I need to do here? :)

VB Code:

'for check box's 1 or 2 only one can be checked
   If Checkbox(1).Value = 1 Then
        Checkbox(2).Value = 0
   End If
 
   If Checkbox(2).Value = 1 Then
         Checkbox(1).Value = 0
   End If

You should really use Option Buttons. They do that withouth the code, but still:

VB Code:

Private Sub Checkbox_Click(Index As Integer)
    Select Case (Index)
        Case 0:
            If Checkbox(0).Value = vbChecked Then Checkbox(1).Value = vbUnchecked
        Case 1:
            If Checkbox(1).Value = vbChecked Then Checkbox(0).Value = vbUnchecked
    End Select
End Sub