How to open Excel XLS file in C#.net

            OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source="+filename+";Extended Properties=Excel 8.0");
            con.Open();
            try
            {
                //Create Dataset and fill with imformation from the Excel Spreadsheet for easier reference
                DataSet myDataSet = new DataSet();
                OleDbDataAdapter myCommand = new OleDbDataAdapter(" SELECT * FROM ["+listname+"$]" , con);
                myCommand.Fill(myDataSet);
                con.Close();
                richTextBox1.AppendText("\nDataSet Filled");

                //Travers through each row in the dataset
                foreach (DataRow myDataRow in myDataSet.Tables[0].Rows)
                {
                    //Stores info in Datarow into an array
                    Object[] cells = myDataRow.ItemArray;
                    //Traverse through each array and put into object cellContent as type Object
                    //Using Object as for some reason the Dataset reads some blank value which
                    //causes a hissy fit when trying to read. By using object I can convert to
                    //String at a later point.
                    foreach (object cellContent in cells)
                    {
                        //Convert object cellContect into String to read whilst replacing Line Breaks with a defined character
                        string cellText = cellContent.ToString();
                        cellText = cellText.Replace("\n", "|");
                        //Read the string and put into Array of characters chars
                        richTextBox1.AppendText("\n"+cellText);
                    }
                }
                //Thread.Sleep(15000);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
                //Thread.Sleep(15000);
            }
            finally
            {
                con.Close();
            }