Adjustment required ? VB.net

Hi

I need help with the highlighted part at the very bottom.

The highlighted part is the code for the "View Information Button"

The problem is, when I choose bus 500 from combo box, the code works fine and shows last four names of passenger array. That's how it is supposed to be.

but then when I choose bus 400, it shows last 8 names plus last four names again, while it is supposed to show only 4 names of second last element of array.

just like when I choose bus 100, it shows all the names of passenger array, while it is supposed to show only first 4 names of the passenger array.

Here is what I have:

Public Class BusReservationForm

Dim destination As String(,) = {
{"12/23/2013", "Atlanta", "Houston"},
{"12/11/2013", "San Francisco", "New York"},
{"12/24/2013", "Seattle", "Miami"},
{"1/12/2014", "Las Vegas", "Chicago"},
{"2/9/2014", "Boston", "Miami"}
}
Dim bus As Integer = 0

Dim passenger As String(,) = {
{"Tim Pedan", "Frank Maxwall",
"Roger Gange", "Kevin Conrad"},
{"Filomina Sylva", "Moe Hernandez",
"Jon Flowers", "John Hathaway"},
{"Brian Alban", "Chris Blaha",
"Simon Hoyle", "Carol Coggins"},
{"Bill Raynolds", "Ronny Jenkins",
"Sheena Jenkins", "Ayu Johnson"},
{"Darryl Jackson", "Sean Byfield",
"Caroline Litchfield", "Leigh Oats"}
}
Dim list As Integer = 0

Private Sub BusReservationForm_Load(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles MyBase.Load

busChoiceComboBox.Items.Insert(0, "100")
busChoiceComboBox.SelectedItem = "100"
busChoiceComboBox.Items.Add("200")
busChoiceComboBox.Items.Add("300")
busChoiceComboBox.Items.Add("400")
busChoiceComboBox.Items.Add("500")

End Sub ' BusReservationForm_Load



Private Sub busChoiceComboBox_SelectedIndexChanged(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles busChoiceComboBox.SelectedIndexChanged

Select Case busChoiceComboBox.SelectedIndex
Case 0
bus = 0
Case 1
bus = 1
Case 2
bus = 2
Case 3
bus = 3
Case 4
bus = 4
End Select

' display info
dateOutputLabel.Text = destination(bus, 0)
departOutputLabel.Text = destination(bus, 1)
arrivalOutputLabel.Text = destination(bus, 2)

End Sub

Private Sub busInfoButton_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles busInfoButton.Click

For row As Integer = 0 To passenger.GetUpperBound(0)
For column As Integer = 0 To passenger.GetUpperBound(1)
displayListBox.Items.Add(passenger(row, column))
Next column
Next row

End Sub
End Class

displayListBox.Items.Clear() i kept and tried ..... still issue exists .. can u please edit my code so works fine 

My best regards

Sunil G