C# open excel

using System.Windows.Forms;using Excel = Microsoft.Office.Interop.Excel; namespace WindowsApplication1{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private void button1_Click(object sender, EventArgs e)        {            Excel.Application xlApp ;            Excel.Workbook xlWorkBook ;            Excel.Worksheet xlWorkSheet ;            object misValue = System.Reflection.Missing.Value;            xlApp = new Excel.ApplicationClass();            xlWorkBook = xlApp.Workbooks.Open("csharp.net-informations.xls", 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);            xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);            MessageBox.Show(xlWorkSheet.get_Range("A1","A1").Value2.ToString());            xlWorkBook.Close(true, misValue, misValue);            xlApp.Quit();            releaseObject(xlWorkSheet);            releaseObject(xlWorkBook);            releaseObject(xlApp);        }        private void releaseObject(object obj)        {            try            {                System.Runtime.InteropServices.Marshal.ReleaseComObject(obj);                obj = null;            }            catch (Exception ex)            {                obj = null;                MessageBox.Show("Unable to release the Object " + ex.ToString());            }            finally            {                GC.Collect();            }        }     }}