AutoCAD .NET :: Copying Selections From One Listbox To Another

I have two listbox controls on my form (lstAvailableLayers and lstLayersToUse).  The lstAvailableLayers listbox gets populated by the following:
 
Public Sub MaindialogTitleText_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Dim myDWG As Autodesk.AutoCAD.ApplicationServices.Document Dim myDB As Autodesk.AutoCAD.DatabaseServices.Database Dim myTransMan As Autodesk.AutoCAD.DatabaseServices.TransactionManager Dim myTrans As
[code]......

There is a button that is supposed to copy the selected items from the lstAvailableLayers listbox to the lstLayersToUse listbox:

Private Sub btnMoveLayers_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnMoveLayers.Click If lstAvailableLayers.SelectedIndex < 0 Then MsgBox("You must select at least one layer", MsgBoxStyle.Exclamation, "Error") Else Dim i As Integer For i = 0 To lstAvailableLayers.SelectedItems.Count - 1 lstLayersToUse.Items.Add(lstAvailableLayers.SelectedItem) Next End If End Sub 

I select 2 layers from the list and hit the button, and the first selected item gets copied twice to the second list. I've looked all over the place and I keep seeing similar code to this that's supposed to work.