จัดเก็บไฟล์โดยให้ผู้ใช้เลือก เองว่าจะจัดเก็บไว้ที่ไหน ต้องเขียนโค้ดยังไงค่ะ

    Private Sub Export2Excel(ByVal filename As String, ByVal data As DataSet)
        Dim grid As New System.Web.UI.WebControls.GridView()
        grid.HeaderStyle.Font.Bold = True
        grid.Font.Size = 8
        grid.DataSource = data
        grid.DataMember = data.Tables(0).TableName
        grid.DataBind()
        Using sw As New StreamWriter(filename)
            Using hw As New HtmlTextWriter(sw)
                grid.RenderControl(hw)
            End Using
        End Using
        MsgBox(filename)
    End Sub

    Protected Sub LinkButton2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles LinkbtnExport.Click
        connectODB()
        Dim da As SqlDataAdapter
        Dim ds As DataSet = New DataSet
        If ckbAll.Checked = True Then
            strSQL = "SELECT * FROM MachineList"
        ElseIf ckbTag.Checked = True AndAlso txtTag.Text = " " Then
            MsgBox("Plese Enter Tag No")
              ElseIf ckbMN.Checked = True AndAlso ckbModel.Checked = True AndAlso ckbBuil.Checked = True AndAlso ckbF.Checked = True Then
            strSQL = "SELECT * FROM MachineList WHERE MachineName = '" & cbxMN.Text & "'And Model = '" & cbxmodel.Text & "' And Building = '" & cbxBuil.Text & "' And Floor = '" & cbxF.Text & "'"
        ElseIf ckbProcess.Checked = True AndAlso ckbLine.Checked = True AndAlso ckbMN.Checked = True Then
            strSQL = "SELECT * FROM MachineList WHERE Process = '" & cbxProcess.Text & "' And  Line = '" & cbxLine.Text & "' And MachineName  = '" & cbxMN.Text & "'"
                          
            End If
        da = New SqlDataAdapter(strSQL, conn)
        da.Fill(ds)
        Dim filename As String
        filename = "C:\\"                             'จะให้ผู้ใช้เลือกที่จัดเก็บเองต้องใช้ยังไงอ่าคะ
        filename &= InputBox("Input Filename : ")
        filename &= ".xls"
        Export2Excel(filename, ds)
        conn.Close()
    End Sub