Customer Accounts Program - visual-studio-2012

Question

I have built a program that allows the user to search for a customer or add a new user with various information related to that customer. However when I run the program I get an error that says An unhandled exception of type 'System.OverflowException' occurred in Microsoft.VisualBasic.dll attached to the telephone number. I am not sure what I am doing wrong here.
My code:
Imports System.IO
Public Class Form1
Dim txtFile As StreamWriter ' object variable
Dim searchFile As StreamReader ' object variable
' structure declaration
Structure CustomerAccounts
Dim Records As StreamReader
Dim LastName As String
Dim FirstName As String
Dim CustomerNumber As String
Dim Address As String
Dim City As String
Dim State As String
Dim ZIPCode As Integer
Dim TelephoneNumber As Int64
Dim AccountBalance As Double
Dim DateOfLastPayment As String
End Structure
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
End Sub
Private Sub SaveCtrlSToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles SaveCtrlSToolStripMenuItem.Click
Dim CustomerRecord As CustomerAccounts ' Structure Variable
' Assigning data to structure variable
CustomerRecord.LastName = txtLast.Text
CustomerRecord.FirstName = txtFirst.Text
CustomerRecord.CustomerNumber = txtNumber.Text
CustomerRecord.Address = txtAddress.Text
CustomerRecord.City = txtCity.Text
CustomerRecord.State = txtState.Text
CustomerRecord.ZIPCode = CInt(txtZIPCode.Text)
CustomerRecord.TelephoneNumber = CInt(txtTelephone.Text)
CustomerRecord.AccountBalance = CDbl(txtAccountBalance.Text)
While CustomerRecord.AccountBalance < 0
CustomerRecord.AccountBalance = CDbl(InputBox("Please enter a non-negative balance"))
End While
CustomerRecord.DateOfLastPayment = CDate(txtPayment.Text)
' Opening a file in append mode
txtFile = File.CreateText("Records.txt")
' Writing data to a file
txtFile.WriteLine(CustomerRecord.LastName)
txtFile.WriteLine(CustomerRecord.FirstName)
txtFile.WriteLine(CustomerRecord.CustomerNumber)
txtFile.WriteLine(CustomerRecord.Address)
txtFile.WriteLine(CustomerRecord.City)
txtFile.WriteLine(CustomerRecord.State)
txtFile.WriteLine(CustomerRecord.ZIPCode)
txtFile.WriteLine(CustomerRecord.TelephoneNumber)
txtFile.WriteLine(CustomerRecord.AccountBalance)
txtFile.WriteLine(CustomerRecord.DateOfLastPayment)
txtFile.Close() ' Close the data file after writing the data
clearFields()
End Sub
Private Sub ExitCtrlQToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles ExitCtrlQToolStripMenuItem.Click
' Close the form
Me.Close()
End Sub
Private Sub SearchToolStripMenuItem1_Click(sender As Object, e As EventArgs) Handles SearchToolStripMenuItem1.Click
' Open a file in read mode
searchFile = File.OpenText("Records.Txt")
Dim lastName As String
Dim flag As Integer
flag = 0
' get the record name from user input
lastName = InputBox("Please enter the last name to search")
Dim CSearchRecord As CustomerAccounts
Try
While Not searchFile.EndOfStream
CSearchRecord.LastName = searchFile.ReadLine()
CSearchRecord.FirstName = searchFile.ReadLine()
CSearchRecord.CustomerNumber = searchFile.ReadLine()
CSearchRecord.Address = searchFile.ReadLine()
CSearchRecord.City = searchFile.ReadLine()
CSearchRecord.State = searchFile.ReadLine()
CSearchRecord.ZIPCode = searchFile.ReadLine()
CSearchRecord.TelephoneNumber = searchFile.ReadLine()
CSearchRecord.AccountBalance = searchFile.ReadLine()
CSearchRecord.DateOfLastPayment = searchFile.ReadLine()
' Compare current record with search record
If CSearchRecord.LastName.Equals(lastName) Then
flag = 1
Exit While
End If
End While
' If record found display txt fields
If flag.Equals(1) Then
txtLast.Text = CSearchRecord.LastName.ToString()
txtFirst.Text = CSearchRecord.FirstName.ToString()
txtNumber.Text = CSearchRecord.CustomerNumber.ToString()
txtAddress.Text = CSearchRecord.Address.ToString()
txtCity.Text = CSearchRecord.City.ToString()
txtState.Text = CSearchRecord.City.ToString()
txtZIPCode.Text = CSearchRecord.ZIPCode.ToString()
txtTelephone.Text = CSearchRecord.TelephoneNumber.ToString()
txtAccountBalance.Text = CSearchRecord.AccountBalance.ToString()
txtPayment.Text = CSearchRecord.DateOfLastPayment.ToString()
Else
' If record not found alert user
MessageBox.Show("Record Not Found")
clearFields()
End If
Catch ex As Exception
End Try
End Sub
Private Sub ReportToolStripMenuItem1_Click(sender As Object, e As EventArgs) Handles ReportToolStripMenuItem1.Click
Dim report As String
report = "Report of Customer Accounts" + vbNewLine
' Open file in read mode
searchFile = File.OpenText("Record.txt")
Try
' Reading the file until end
While Not searchFile.EndOfStream
report += searchFile.ReadLine() + " "
report += searchFile.ReadLine() + " "
report += searchFile.ReadLine() + " "
report += searchFile.ReadLine() + " "
report += vbNewLine
End While
Catch ex As Exception
End Try
' Display file Content as report
MessageBox.Show(report)
End Sub
Private Sub clearFields()
txtAccountBalance.Clear()
txtAddress.Clear()
txtCity.Clear()
txtFirst.Clear()
txtLast.Clear()
txtNumber.Clear()
txtPayment.Clear()
txtState.Clear()
txtTelephone.Clear()
txtZIPCode.Clear()
End Sub
End Class
Any help offered would be greatly appreciated. I just need to know how to fix this.