Asp.net with C# doubts

my code is there, but i cannot count second white empty space pls help me.

using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;
using System.IO;





public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

}
protected void Button1_Click(object sender, EventArgs e)
{

//string s3 = TextBox1.Text.ToString();
// string s3 = Server.MapPath("~/cibilguide.txt");
string path = @"C:\Users\vijayanarayanakumarm\Documents\Visual Studio 2008\Projects\CIBIL\cibilguide.txt";
//StreamReader sr = new StreamReader("");
using (StreamReader reader = new StreamReader(path))
{
string s3 = reader.ReadLine();





////for (int i = 0; i < s3.Length; i++)
////{

//// // MessageBox.Show(strOriginal[i].ToString());



////}


while ((s3 = reader.ReadLine()) != null)
{



string st = s3.Substring(0, 4); //1234
string ver = s3.Substring(4, 2); //12
string mrn = s3.Substring(6, 25);//1234567890123456789012345
// string fu = s3.Substring(31, 2);//12

//string em = s3.Substring(33, 30);//123456789012345678901234567890
//string epswd = s3.Substring(63, 30); //123456789012345678901234567890
//string epos = s3.Substring(93, 2);//12
//string eamt = s3.Substring(95, 09);//123456789
//string fus = s3.Substring(104, 3);//123
//string styp = s3.Substring(107, 02);//12
//string of = s3.Substring(109, 02);//12
//string rsz = s3.Substring(111, 1);//1
//string iom = s3.Substring(112, 02);//12
//string aum = s3.Substring(114, 01);//1



Response.Write("segement tag is :" + st + "<br />");

Response.Write("Version is :" + ver + "<br />");
Response.Write("mrn is :" + mrn + "<br />");
Response.Write("Future Use is :" + fu + "<br />");
//Response.Write("EM User ID is :" + em + "<br />");
//Response.Write("Epassword is :" + epswd + "<br />");
//Response.Write("E purpose is :" + epos + "<br />");
//Response.Write("E amount is :" + eamt + "<br />");
//Response.Write("Future use is :" + fus + "<br />");
//Response.Write("score type is :" + styp + "<br />");
//Response.Write("output format is :" + of + "<br />");
//Response.Write("Response size is :" + rsz + "<br />");
//Response.Write("input output method is :" + iom + "<br />");
//Response.Write("authdication met is :" + aum + "<br />");


// SqlConnection conn = new SqlConnection("Data Source=10.9.58.75;Initial Catalog=SampleDB;User ID=sa;Password=Chola@123");
// SqlCommand st1 = new SqlCommand("insert into cibil(SermentTag) values('" + @st + "')", conn);
// SqlCommand ver1 = new SqlCommand("insert into cibil(versionn) values('" + @ver + "')", conn);
// SqlCommand mrn1 = new SqlCommand("insert into cibil(MemberReference) values('" + @mrn + "')", conn);
// SqlCommand fu1 = new SqlCommand("insert int