Export Excel from Data Grid

private void button1_Click(object sender, System.EventArgs e)
        {


            Excel.Application oXL;
            Excel._Workbook oWB;
            Excel._Worksheet oSheet;
            Excel.Range oRng;
            FillExcel();
            try
            {
                //Start Excel and get Application object.
                oXL = new Excel.Application();
                oXL.Visible = true;


                //Get a new workbook.
                oWB = (Excel._Workbook)(oXL.Workbooks.Add(Missing.Value));
                oSheet = (Excel._Worksheet)oWB.ActiveSheet;

                //Add table headers going cell by cell.
                oSheet.Cells[1, 1] = "No";
                oSheet.Cells[1, 2] = "Message ID";
               

                //Format A1:F1 as bold, vertical alignment = center.
                oSheet.get_Range("A1", "C1").Font.Bold = true;
                oSheet.get_Range("A1", "C1").VerticalAlignment =
                    Excel.XlVAlign.xlVAlignCenter;

                // Create an array to multiple values at once.
                string[,] saNames = new string[5, 2];
                //this.dgtbcE_Name.MappingName = "MessageID";
                // saNames[0, 0] = dgtbcE_NamedgtbcE_Name.ToString;
                saNames[0, 1] = "Smith";
                saNames[1, 0] = "Tom";
               

                //Fill A2:B6 with an array of values (First and Last Names).
                oSheet.get_Range("A2", "B6").Value2 = saNames;

                //Fill C2:C6 with a relative formula (=A2 & " " & B2).
                oRng = oSheet.get_Range("C2", "C6");
                oRng.Formula = "=A2 & \" \" & B2";

                //Fill D2:D6 with a formula(=RAND()*100000) and apply format.
                oRng = oSheet.get_Range("D2", "D6");
                oRng.Formula = "=RAND()*100000";
                oRng.NumberFormat = "$0.00";

                //AutoFit columns A:D.
                oRng = oSheet.get_Range("A1", "C1");
                oRng.EntireColumn.AutoFit();

                 //Make sure Excel is visible and give the user control
                //of Microsoft Excel's lifetime.
                oXL.Visible = true;
                oXL.UserControl = true;
            }

private void loadPage()
		{
            
            
			string strSql = "";
			int intSkip = 0;

			intSkip = (this.mintCurrentPage * this.mintPageSize);

			string ItemList = SearchList.SelectedItem.ToString();
            

            //Return All rows and columns in Message Trace Table
            if (ItemList == "ALL")
            {
                
                strSql = "SELECT Top " + this.mintPageSize +
                                  " * FROM tblTraceMessages WHERE MessageId NOT IN " +
                                  "(SELECT TOP " + intSkip + " ID FROM tblTraceMessages)";
            }
	SqlCommand cmd = this.mcnSample.CreateCommand();
			cmd.CommandText = strSql;
            
			SqlDataAdapter da = new SqlDataAdapter(cmd);
			
			DataSet ds = new DataSet();
			da.Fill(ds, "tblTraceMessages");

// Populate Data Grid
			this.dgEmp.DataSource = ds.Tables["tblTraceMessages"].DefaultView;

			// Show Status
			this.lblStatus.Text = (this.mintCurrentPage + 1).ToString() + " / " + this.mintPageCount.ToString();
 
			cmd.Dispose();
			da.Dispose();
			ds.Dispose();