Moving file contents into an array - arrays

Question

Im currently working on getting this piece of code to work so that I can read a text file, move the contents into an array and then display a certain column (such as price)
Imports System.IO
Public Class Form1
Dim FileName As String
Dim i As Integer = 0
Dim Alpha As Integer = 0
Dim Products(31) As String
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
FileName = "Products.txt"
End Sub
Private Sub btnCreateArray_Click(sender As Object, e As EventArgs) Handles btnCreateArray.Click
Using MyReader As New Microsoft.VisualBasic.FileIO.TextFieldParser("Products.txt")
MyReader.TextFieldType = FileIO.FieldType.Delimited
MyReader.SetDelimiters(",")
Dim currentRow As String()
While Not MyReader.EndOfData
currentRow = MyReader.ReadFields()
Dim currentField As String
For Each currentField In currentRow
'MsgBox(currentField)
'txtShowNo.Text = currentField
'txtShowP.Text = i
i = i + 1
Products(i) = currentField
Next
End While
End Using
Do While Alpha <= i
If InStr((txtFileSearch.Text), (Products(Alpha))) Then
lstDisplayFile.Items.Add(Products(Alpha))
Alpha = Alpha + 1
End If
Loop
End Sub
Private Sub btn_Click(sender As Object, e As EventArgs) Handles btn.Click
txtFileSearch.Text = ""
End Sub
Private Sub btnAddToFilePrintFile_Click(sender As Object, e As EventArgs) Handles btnAddToFilePrintFile.Click
Dim Name As String
Dim SName As String
Dim IDNo As Integer
Name = txtName.Text
SName = txtSName.Text
IDNo = txtIDNo.Text
FileOpen(1, FileName, OpenMode.Append) ' create a new empty file & open it in append mode'
WriteLine(1, IDNo, Name, SName) ' Writes a line of data'
FileClose(1)
txtName.Text = ""
txtSName.Text = ""
txtIDNo.Text = ""
txtName.Focus()
End Sub
End Class
The program crashes on this line of code:
lstDisplayFile.Items.Add(Products(Alpha))
along with the following message :
An unhandled exception of type 'System.ArgumentNullException' occurred in System.Windows.Forms.dll
Alpha is my counter, and my thought process behind this was that if the input within the textbox is currently in the array, it will display the completed text in the array.
Here is the current contents within my text file :
"£5.00","50"
"£2.50","30"
If anyone could help me solve this I would be appreciative :)