Reading/Writing Excel in C# using Interop

Add references to :
Microsoft Excel 10.0/11 Object Library using "add reference->com" tab. The following code shows example of reading and writing the xls:

using System;
using System.Collections.Generic;
using System.Text;
using Excel;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            string path = @"C:\Documents and Settings\shivps\Desktop\cbit_codef\CBIT_CODEF\New Microsoft Excel Worksheet.xls";
            Excel.ApplicationClass app = new ApplicationClass();
            app.ShowWindowsInTaskbar = false;

            Excel.Workbook wb = app.Workbooks.Open(
                  path,
                  0,
                  false,
                  5,
                  "",
                  "",
                  true,
                  Excel.XlPlatform.xlWindows,
                  "\t",
                  true,
                  false,
                  0,
                  true,
                  1,
                  0);

            Excel.Worksheet wsAuthor = null;
            foreach (Excel.Worksheet ws in wb.Worksheets)
            {
                if (string.Compare("author", ws.Name, true) == 0)
                {
                    wsAuthor = ws;
                    break;
                }
            }

            // read all records
            int row = 2; // leave first row
            while (true)
            {
                if (((Excel.Range)wsAuthor.Cells[row, 1]).Value2 == null ||
                    ((Excel.Range)wsAuthor.Cells[row, 2]).Value2 == null ||
                    ((Excel.Range)wsAuthor.Cells[row, 3]).Value2 == null ||
                    ((Excel.Range)wsAuthor.Cells[row, 4]).Value2 == null)
                {
                    break;
                }
                string first = ((Excel.Range)wsAuthor.Cells[row, 1]).Value2.ToString();
                string second = ((Excel.Range)wsAuthor.Cells[row, 2]).Value2.ToString();
                string login = ((Excel.Range)wsAuthor.Cells[row, 3]).Value2.ToString();
                string pass = ((Excel.Range)wsAuthor.Cells[row, 4]).Value2.ToString();

                // create user
                string status = "pass";
                string error = "no error";

                // update xls
                wsAuthor.Cells[row, 5] = status;
                wsAuthor.Cells[row, 6] = error;
                row++;
            }

            wb.Save();
            wb.Close(false, null, null);
            app.Quit();
        }
        
    }
}