Populating a listbox

I'm creating an application to cross reference part numbers to three major brands. The part numbers are stored in a comma delimited text file and read into a two dimensional array during the form load event. I can't seem to figure out whats wrong. If anyone can chime in, I would really appreciate it. It isn't completed yet obviously.


Option Strict On
Imports Microsoft.VisualBasic.FileIO

Public Class PartsForm

Private PartsNumberTextFieldParser As TextFieldParser
Private PartsArrayString(,) As String

Private Sub ExitButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ExitButton.Click
' Terminates the program.

Me.Close()
End Sub

Private Sub ClearButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ClearButton.Click
' Clears the form of all previously selected data.

BrandListBox.SelectedIndex = -1
TheirNumberListBox.Items.Clear()
OurNumberOutputLabel.Text = ""

End Sub

Private Sub PartsForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
' Instantiates the TextFieldParser and populates the array.

Dim PartsString As String = "TextFile.txt"
Dim FieldString() As String
Dim RowInteger, ColumnInteger As Integer

Try
PartsNumberTextFieldParser = New TextFieldParser(PartsString)
PartsNumberTextFieldParser.TextFieldType = FieldType.Delimited
PartsNumberTextFieldParser.SetDelimiters(",")

Do While Not PartsNumberTextFieldParser.EndOfData
FieldString = PartsNumberTextFieldParser.ReadFields()

For RowInteger = 0 To 8
For ColumnInteger = 0 To 3
PartsArrayString(RowInteger, ColumnInteger) = ""
Next ColumnInteger
Next RowInteger
Loop
Catch ex As Exception

End Try
End Sub

Private Sub TheirNumberListBox_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TheirNumberListBox.SelectedIndexChanged
'ListBox is populated with the parts number of the corresponding brand.


End Sub

Private Sub BrandListBox_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)
' Populates the TheirNumberListBox with respective part numbers.

Dim RowIndexInteger As Integer

Try
RowIndexInteger = BrandListBox.SelectedIndex
If RowIndexInteger <> -1 Then
For RowIndexInteger = 0 To 8
TheirNumberListBox.Text = PartsArrayString(RowIndexInteger,? )
Next
End If

Catch ex As Exception

End Try
End Sub
End Class