Создание графика Excel

Imports System.Runtime.InteropServices
Public Class Form1
    Private _xlApp As EX.Application
    Private _xlBook As EX.Workbook
    Private _xlSheet As EX.Worksheet
    Private xRange As EX.Range
    Private data1(), data2() As Integer
    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        'формируем данные для графика
        data1 = {-1, 0, 2, 5, -9, 12, 26, 21}
        data2 = {-10, -2, 1, 14, 5, 8, 22, 14}
        'открываем новую книгу в Excel
        _xlApp = New EX.Application
        _xlApp.SheetsInNewWorkbook = 1
        _xlBook = _xlApp.Workbooks.Add()
        _xlSheet = _xlBook.ActiveSheet
        _xlApp.DisplayAlerts = False
        _xlApp.Visible = True
    End Sub
    Private Sub Data_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        'добавляем данные {Y1,Y2} на лист
        Dim n As Integer = data1.Length + 2 - 1
        _xlSheet.Range("A1").Value = "Y1"
        xRange = _xlSheet.Range("A2", "A" & n.ToString)
        xRange.Value = _xlApp.WorksheetFunction.Transpose(data1)
        _xlSheet.Range("B1").Value = "Y2"
        xRange = _xlSheet.Range("B2", "B" & n.ToString)
        xRange.Value = _xlApp.WorksheetFunction.Transpose(data2)
        xRange = _xlSheet.Range("A2", "B" & n.ToString)
    End Sub
    Private Sub Graph_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
        'рисуем график
        Dim ch As EX.Chart = _xlApp.Charts.Add()
        ch.ChartType = EX.XlChartType.xlLine
        ch.SetSourceData(xRange, EX.XlRowCol.xlColumns)
        ch.Location(Microsoft.Office.Interop.Excel.XlChartLocation.xlLocationAsObject, _xlSheet.Name)
        ch = _xlApp.ActiveChart
        Dim sr1 As EX.Series = ch.SeriesCollection(1)
        Dim sr2 As EX.Series = ch.SeriesCollection(2)
        sr1.Border.Color = Color.Red
        sr1.Border.Weight = EX.XlBorderWeight.xlThick
        sr2.Border.Color = Color.Green
        sr2.Border.Weight = EX.XlBorderWeight.xlMedium
    End Sub
    Private Sub Form1_FormClosing(sender As System.Object, e As System.Windows.Forms.FormClosingEventArgs) Handles MyBase.FormClosing
        Marshal.ReleaseComObject(_xlSheet)
        _xlBook.Close(False)
        _xlApp.Workbooks.Close()
        Marshal.ReleaseComObject(_xlBook)
        _xlApp.Quit()
        Marshal.ReleaseComObject(_xlApp)
        _xlApp = Nothing
    End Sub
End Class