Private Sub btnGo1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGo1.Click
 
        aiidb2.ExcludeDuplicates = False
 
        If (txtDelim1.Text = "") Then
            MessageBox.Show("You MUST enter a field delimiter for the CSV input file")
            txtDelim1.Focus()
            GoTo lab_end
        End If
 
        If (txtAimsNo.Text = "") Then
            MessageBox.Show("You MUST enter an AIMS number for the input file")
            txtAimsNo.Focus()
            GoTo lab_end
        End If
 
        If (txtReceiptNo.Text = "") Then
            MessageBox.Show("You MUST enter a contractor receipt number for the input file")
            txtReceiptNo.Focus()
            GoTo lab_end
        End If
 
        If aiidb2.DuplicatesFound Then
            Dim dlgRes As DialogResult
            dlgRes = MessageBox.Show( _
                  "This contractor return contains duplicate rows." + vbCr + vbLf + _
                  "Do you want to load the duplicates into SOURCEData?", "File Contains Duplicate Rows", _
            MessageBoxButtons.YesNoCancel, _
                  MessageBoxIcon.Question)
            If dlgRes = Windows.Forms.DialogResult.Yes Then
                aiidb2.ExcludeDuplicates = False
            ElseIf dlgRes = Windows.Forms.DialogResult.No Then
                aiidb2.ExcludeDuplicates = True
            Else
                GoTo lab_end
            End If
        End If
 
        ' Get current date/time and format it
        aiidb2.GetDateTime()
        aiidb2.FormatDateTime()
 
        aiidb2.NowDate = aiidb2.Now.Year.ToString + aiidb2.NowMonth + aiidb2.NowDay
        aiidb2.NowTime = aiidb2.NowHour + aiidb2.NowMinute
 
        If aiidb2.ExcludeDuplicates Then
            'Create file of duplicates
            aiidb2.DuplicatesFile()
        End If
 
        ' ***** Initialise variables
        aiidb2.ErrorRate = 0
 
        'Test if replayed error file
        If (aiidb2.ErrorFile) Then
            If MessageBox.Show("This is an error file." + vbCr + vbLf + _
            "Has it been corrected?" + vbCr + vbLf + _
            "Are you sure you want to replay this error file?", "Error File", _
            MessageBoxButtons.YesNo, MessageBoxIcon.Question) _
            = Windows.Forms.DialogResult.Yes Then
                'do Nothing
            Else
                GoTo lab_end
            End If
        End If
 
        aiidb2.CreateOriginalFileName()
 
        Me.Cursor = Cursors.WaitCursor
 
        ' Call to the lengthy process here
        'Dim t As New Thread(AddressOf aiidb2.LoadData)
        'AddHandler aiidb2.FinishedDataLoading, AddressOf FinishedDataLoadingEventHandler
        't.Start()
 
lab_end:
 
    End Sub

        'If no errors, tidy files up
        If (aiidb2.ErrorCount = 0) Then
            'Archive orignal file here
            File.Move(aiidb2.FilePath + aiidb2.OriginalFileName, aiidb2.FilePathArchived + aiidb2.OriginalFileName)
 
            ' TODO: Possibly set DataLoadRequired flag on DB to false after successful load
 
            ' TODO: Business decision on whether to delete replayed / corrected errorfile or Archive
            ' Currently archive the file
 
            ' ***** DELETE ErrorFile *****
            'Delete replayed error file (this can be reintroduced if neccessary, decided to keep corrected error file)
            'If (aiidb2.errorFile) Then
            'File.Delete(filePath + FileName)
            'End If
 
            ' ***** ARCHIVE ErrorFile *****
            'Archive replayed / corrected errorfile
            If (aiidb2.ErrorFile) Then
                File.Move(aiidb2.FileName, aiidb2.FilePathArchived + aiidb2.FileNameNoPath)
            End If
 
            'MessageBox.Show("Original RAW data archived & any replayed error file deleted")
        End If
 
        'Calculate error rate as percentage
        aiidb2.ErrorRate = Math.Round(((aiidb2.ErrorCount / aiidb2.EndCount) * 100), 2)
 
        Me.Cursor = Cursors.Default
 
        If (aiidb2.DuplicatesFound And aiidb2.ExcludeDuplicates) Then
            MessageBox.Show(aiidb2.SuccessCount & " Rows Inserted into SOURCEData" & vbCr & vbLf & vbCr & vbLf & aiidb2.Dups.Count.ToString & " Rows written to DUPLICATES file" & vbCr & vbLf & vbCr & vbLf & aiidb2.ErrorCount & " Rows written to ERROR file" & vbCr & vbLf & vbCr & vbLf & "Error rate: " & aiidb2.ErrorRate & "%", "Load Summary")
        Else
            MessageBox.Show(aiidb2.SuccessCount & " Rows Inserted into SOURCEData" & vbCr & vbLf & vbCr & vbLf & aiidb2.ErrorCount & " Rows written to ERROR file" & vbCr & vbLf & vbCr & vbLf & "Error rate: " & aiidb2.ErrorRate & "%", "Load Summary")
        End If
 
        lblFilename1.Visible = False
        lblFilename1.Text = Nothing
        aiidb2.FileName = Nothing
        lblDelim1.Visible = False
        lblAimsNo.Visible = False
        lblReceiptNo.Visible = False
        txtDelim1.Visible = False
        txtAimsNo.Text = ""
        txtAimsNo.Visible = False
        txtReceiptNo.Text = ""
        txtReceiptNo.Visible = False
        btnBrowseData.Visible = False
        btnGo1.Visible = False
        panData.Visible = False

Imports System
Imports System.ComponentModel
Imports System.Threading
Imports System.Windows.Forms
 
Public Class Form1
   Inherits Form
 
   ' This delegate enables asynchronous calls for setting
   ' the text property on a TextBox control.
   Delegate Sub SetTextCallback([text] As String)
 
   ' This thread is used to demonstrate both thread-safe and
   ' unsafe ways to call a Windows Forms control.
   Private demoThread As Thread = Nothing
 
   ' This BackgroundWorker is used to demonstrate the 
   ' preferred way of performing asynchronous operations.
   Private WithEvents backgroundWorker1 As BackgroundWorker
 
   Private textBox1 As TextBox
   Private WithEvents setTextUnsafeBtn As Button
   Private WithEvents setTextSafeBtn As Button
   Private WithEvents setTextBackgroundWorkerBtn As Button
 
   Private components As System.ComponentModel.IContainer = Nothing
 
 
   Public Sub New()
      InitializeComponent()
    End Sub
 
 
   Protected Overrides Sub Dispose(disposing As Boolean)
      If disposing AndAlso (components IsNot Nothing) Then
         components.Dispose()
      End If
      MyBase.Dispose(disposing)
    End Sub
 
 
   ' This event handler creates a thread that calls a 
   ' Windows Forms control in an unsafe way.
    Private Sub setTextUnsafeBtn_Click( _
    ByVal sender As Object, _
    ByVal e As EventArgs) Handles setTextUnsafeBtn.Click
 
        Me.demoThread = New Thread( _
        New ThreadStart(AddressOf Me.ThreadProcUnsafe))
 
        Me.demoThread.Start()
    End Sub
 
 
   ' This method is executed on the worker thread and makes
   ' an unsafe call on the TextBox control.
   Private Sub ThreadProcUnsafe()
      Me.textBox1.Text = "This text was set unsafely."
   End Sub 
 
   ' This event handler creates a thread that calls a 
   ' Windows Forms control in a thread-safe way.
    Private Sub setTextSafeBtn_Click( _
    ByVal sender As Object, _
    ByVal e As EventArgs) Handles setTextSafeBtn.Click
 
        Me.demoThread = New Thread( _
        New ThreadStart(AddressOf Me.ThreadProcSafe))
 
        Me.demoThread.Start()
    End Sub
 
 
   ' This method is executed on the worker thread and makes
   ' a thread-safe call on the TextBox control.
   Private Sub ThreadProcSafe()
      Me.SetText("This text was set safely.")
    End Sub
 
   ' This method demonstrates a pattern for making thread-safe
   ' calls on a Windows Forms control. 
   '
   ' If the calling thread is different from the thread that
   ' created the TextBox control, this method creates a
   ' SetTextCallback and calls itself asynchronously using the
   ' Invoke method.
   '
   ' If the calling thread is the same as the thread that created
    ' the TextBox control, the Text property is set directly. 
 
    Private Sub SetText(ByVal [text] As String)
 
        ' InvokeRequired required compares the thread ID of the
        ' calling thread to the thread ID of the creating thread.
        ' If these threads are different, it returns true.
        If Me.textBox1.InvokeRequired Then
            Dim d As New SetTextCallback(AddressOf SetText)
            Me.Invoke(d, New Object() {[text]})
        Else
            Me.textBox1.Text = [text]
        End If
    End Sub
 
   ' This event handler starts the form's 
   ' BackgroundWorker by calling RunWorkerAsync.
   '
   ' The Text property of the TextBox control is set
   ' when the BackgroundWorker raises the RunWorkerCompleted
   ' event.
    Private Sub setTextBackgroundWorkerBtn_Click( _
    ByVal sender As Object, _
    ByVal e As EventArgs) Handles setTextBackgroundWorkerBtn.Click
        Me.backgroundWorker1.RunWorkerAsync()
    End Sub
 
 
   ' This event handler sets the Text property of the TextBox
   ' control. It is called on the thread that created the 
   ' TextBox control, so the call is thread-safe.
   '
   ' BackgroundWorker is the preferred way to perform asynchronous
   ' operations.
    Private Sub backgroundWorker1_RunWorkerCompleted( _
    ByVal sender As Object, _
    ByVal e As RunWorkerCompletedEventArgs) _
    Handles backgroundWorker1.RunWorkerCompleted
        Me.textBox1.Text = _
        "This text was set safely by BackgroundWorker."
    End Sub
 
   #Region "Windows Form Designer generated code"
 
 
   Private Sub InitializeComponent()
      Me.textBox1 = New System.Windows.Forms.TextBox()
      Me.setTextUnsafeBtn = New System.Windows.Forms.Button()
      Me.setTextSafeBtn = New System.Windows.Forms.Button()
      Me.setTextBackgroundWorkerBtn = New System.Windows.Forms.Button()
      Me.backgroundWorker1 = New System.ComponentModel.BackgroundWorker()
      Me.SuspendLayout()
      ' 
      ' textBox1
      ' 
      Me.textBox1.Location = New System.Drawing.Point(12, 12)
      Me.textBox1.Name = "textBox1"
      Me.textBox1.Size = New System.Drawing.Size(240, 20)
      Me.textBox1.TabIndex = 0
      ' 
      ' setTextUnsafeBtn
      ' 
      Me.setTextUnsafeBtn.Location = New System.Drawing.Point(15, 55)
      Me.setTextUnsafeBtn.Name = "setTextUnsafeBtn"
      Me.setTextUnsafeBtn.TabIndex = 1
      Me.setTextUnsafeBtn.Text = "Unsafe Call"
      ' 
      ' setTextSafeBtn
      ' 
      Me.setTextSafeBtn.Location = New System.Drawing.Point(96, 55)
      Me.setTextSafeBtn.Name = "setTextSafeBtn"
      Me.setTextSafeBtn.TabIndex = 2
      Me.setTextSafeBtn.Text = "Safe Call"
      ' 
      ' setTextBackgroundWorkerBtn
      ' 
      Me.setTextBackgroundWorkerBtn.Location = New System.Drawing.Point(177, 55)
      Me.setTextBackgroundWorkerBtn.Name = "setTextBackgroundWorkerBtn"
      Me.setTextBackgroundWorkerBtn.TabIndex = 3
      Me.setTextBackgroundWorkerBtn.Text = "Safe BW Call"
      ' 
      ' backgroundWorker1
      ' 
      ' 
      ' Form1
      ' 
      Me.ClientSize = New System.Drawing.Size(268, 96)
      Me.Controls.Add(setTextBackgroundWorkerBtn)
      Me.Controls.Add(setTextSafeBtn)
      Me.Controls.Add(setTextUnsafeBtn)
      Me.Controls.Add(textBox1)
      Me.Name = "Form1"
      Me.Text = "Form1"
      Me.ResumeLayout(False)
      Me.PerformLayout()
   End Sub 'InitializeComponent 
 
   #End Region
 
   <STAThread()>  _
   Shared Sub Main()
      Application.EnableVisualStyles()
      Application.Run(New Form1())
    End Sub
End Class