Activate layers that are in a checkbox list

Question

I'm trying to do a code to activate layers that are in a checkbox list, the code that I'm trying to use is this:

    MxDoc = My.ArcMap.Document
    Maps = MxDoc.Maps


    If chxActivated.SelectedItem = True Then
        GxLayer.Layer.Visible = True [COLOR="#FF0000"]HERE IS THE PROBLEM[/COLOR]
        MxDoc.UpdateContents()
        MxDoc.ActiveView.Refresh()
     End If

I add the layers with this code

    MxDoc = My.ArcMap.Document
    Map = MxDoc.FocusMap
    'new layer
    GxLayer = New GxLayer
    GxFile = GxLayer
    'Layer file path
    GxFile.Path = "C:\Layers\Aditional Information.lyr"
    'Add the new layer to ArcMap
    Map.AddLayer(GxLayer.Layer)
    'Add the layer invisible
    GxLayer.Layer.Visible = False
    'Refresh the view
    MxDoc.ActiveView.Refresh()
End Sub

Thank you!

Answer 1

I've done just in case someone need it

 Dim i As Integer
           Dim SelectedIndex As Integer = chxActivated.SelectedIndex
    Dim chkstate As CheckState
    MxDoc = My.ArcMap.Document
    Maps = MxDoc.Maps
    Map = MxDoc.FocusMap
    PageLayout = MxDoc.PageLayout
    i = 0
    intMapCount = Maps.Count

    chkstate = chxActivated.GetItemCheckState(SelectedIndex)


    For i = 0 To chxActivated.Items.Count - 1
        If chkstate = CheckState.Checked Then
            Map.Layer(SelectedIndex).Visible = True
            Map.MapScale = 15000
            MxDoc.ActiveView.Refresh()
        Else
            Map.Layer(SelectedIndex).Visible = False
            MxDoc.ActiveView.Refresh()
        End If
    Next

Cheers!