How to enable a button when an item is selected in a listBox

[JENKINS]

I'm stuck on a part of my assignment and wondering if someone could point me in the right direction.

Here's my problem, I have set my listBox button_up to disabled, but I need it to enable when there is at least 1 selected item in the listBox, here's my code for the remove button:

Private Sub btnRemove_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnRemove.Click
 
      If listBox.SelectedItems ' need selectedItem to = something??? Then
 
            Me.btnRemove.Enabled = True
        End If
 
        Dim item As String = listBox.SelectedItem
        Dim index As Integer = listBox.SelectedIndex
        listBox.Items.RemoveAt(index)
        listBox.Items.Insert(index - 1, item)
        listBox.SelectedIndex = index - 1
 
end sub

Thanks for any help.