Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'Put user code to initialize the page here
        ShowUserAuthenticationControls()
        HideFileUploadControls()
    End Sub

    Function ShowUserAuthenticationControls()
        ' Show the user authentication controls
        lblUsername.Visible = True
        lblPassword.Visible = True
        txtUsername.Visible = True
        txtPassword.Visible = True
        btnSubmit.Visible = True
        btnReUpload.Visible = False
    End Function

    Function HideUserAuthenticationControls()
        ' Hide the user authentication controls
        lblUsername.Visible = False
        lblPassword.Visible = False
        txtUsername.Visible = False
        txtPassword.Visible = False
        btnSubmit.Visible = False
        btnReUpload.Visible = False
    End Function

    Function ShowFileUploadControls()
        'Hide the user authentication controls
        uploadFilePath.Visible = True
        txtFileName.Visible = True
        btnImage.Visible = True
        lblFilename.Visible = True
        lblTitle.InnerHtml = "Upload an Image"
    End Function

    Function HideFileUploadControls()
        'Hide the user authentication controls
        uploadFilePath.Visible = False
        txtFileName.Visible = False
        lblFilename.Visible = False
        btnImage.Visible = False
        HyperLink1.Visible = False
    End Function

    Function ResetUserAuthenticationControls()
        'Reset the user authentication controls
        lblTitle.InnerHtml = "Upload an Image"
        txtUsername.Value = ""
        txtPassword.Value = ""
    End Function

    Private Sub btnImage_ServerClick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnImage.ServerClick
        If txtFileName.Value = "" Then
            lblTitle.InnerHtml = "Error: You must enter a file name."
            HideUserAuthenticationControls()
            ShowFileUploadControls()
            Return
        End If
        If Not (uploadFilePath.PostedFile Is Nothing) Then
            Try


                ' Enter the code below to upload the file

                 










                lblTitle.InnerHtml = "File uploaded successfully"

                lblMessage.InnerHtml = "Your file was uploaded successfully to <br>" & _
                "<b>" & strFilePath & "\" & _
                txtFileName.Value & "</b><br>on the Web server."

                HideFileUploadControls()
                HideUserAuthenticationControls()
                lblMessage.Visible = True
                btnReUpload.Visible = True

                HyperLink1.NavigateUrl = "http://localhost/chapter4/" & txtFileName.Value
                HyperLink1.Visible = True

            Catch exc As Exception
                lblTitle.InnerHtml = "Error saving file"
            End Try
        End If
    End Sub

    Private Sub btnSubmit_ServerClick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSubmit.ServerClick
        If ((txtUsername.Value = "Course") And (txtPassword.Value = "Technology")) Then
            ShowFileUploadControls()
            HideUserAuthenticationControls()
        Else
            lblTitle.InnerHtml = "Error logging in"
            Return
        End If
    End Sub

    Private Sub btnReUpload_ServerClick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnReUpload.ServerClick
        ResetUserAuthenticationControls()
        HideUserAuthenticationControls()
        ShowFileUploadControls()
        txtFileName.Value = ""
        btnReUpload.Visible = False
        lblMessage.Visible = False
    End Sub