Creating an Excel Application in C#

using Microsoft.Office.Interop.Excel;
using System.Windows.Forms;
 
 
 
 
public class Form1
{
	private void Button1_Click(object sender, EventArgs e)
	{
		Application appXL = default(Application);
		Workbook wbXl = default(Workbook);
		Worksheet shXL = default(Worksheet);
		Range raXL = default(Range);
		// Start Excel and get Application object.
		appXL = CreateObject("Excel.Application");
		appXL.Visible = true;
		// Add a new workbook.
		wbXl = appXL.Workbooks.Add;
		shXL = wbXl.ActiveSheet;
		// Add table headers going cell by cell.
		shXL.Cells(1, 1).Value = "First Name";
		shXL.Cells(1, 2).Value = "Last Name";
		shXL.Cells(1, 3).Value = "Full Name";
		shXL.Cells(1, 4).Value = "Specialization";
		// Format A1:D1 as bold, vertical alignment = center.
		object with_1 = shXL.Range("A1", "D1");
		with_1.Font.Bold = true;
		with_1.VerticalAlignment = XlVAlign.xlVAlignCenter;
		// Create an array to set multiple values at once.
		string[,] students = new string[6, 3];
		students[0, 0] = "Lyndon";
		students[0, 1] = "Bermoy";
		students[1, 0] = "Novee";
		students[1, 1] = "Dumanig";
		students[2, 0] = "Aga";
		students[2, 1] = "Bermoy";
		students[3, 0] = "Don";
		students[3, 1] = "Bermzkiee";
		students[4, 0] = "Sourcecodester";
		students[4, 1] = "TheBest";
		// Fill A2:B6 with an array of values (First and Last Names).
		shXL.Range("A2", "B6").Value = students;
		// Fill C2:C6 with a relative formula (=A2 & " " & B2).
		raXL = shXL.Range("C2", "C6");
		raXL.Formula = "=A2 & \" \" & B2";
		// Fill D2:D6 values.
		shXL.Cells(2, 4).Value = "Programming";
		shXL.Cells(3, 4).Value = "Mechatronics";
		shXL.Cells(4, 4).Value = "Robotics";
		shXL.Cells(5, 4).Value = "Mathmematics";
		shXL.Cells(6, 4).Value = "Best Website";
		// AutoFit columns A:D.
		raXL = shXL.Range("A1", "D1");
		raXL.EntireColumn.AutoFit();
		// Make sure Excel is visible and give the user control
		// of Excel's lifetime.
		appXL.Visible = true;
		appXL.UserControl = true;
		// Release object references.
		raXL = null;
		shXL = null;
		wbXl = null;
		appXL.Quit();
		appXL = null;
		return;
Err_Handler:
		MsgBox(Err.Description, vbCritical, "Error: " + Err.Number);
	}
}