Dynamically creating control through textbox and button Control are add

[goltu]

It   suceesful      in   first   time   you   enter   number   .But   if   remove   that   umber   again   enter it   is   adding .
Like   first   input   4   in textbox   and   enter .remove   that   number   textbox   input   6 and   enter .
it   "adding   4+6"      4   alright   plus   new   6   more   will   display   means   totally   10 .
using System;
using System.Collections;
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;
public partial class assigned: System.Web.UI.Page
{
      protected void Page_Load(object sender, EventArgs e)
      {
            if (IsPostBack && DDLCount > 0)
            {
                  CreateDropDownLists();
            }
 
      }
      public int DDLCount
      {
            get
            {
                  // Try to get an instance of the DDLCount ViewState object
                  object temp = ViewState["DDLCount"];
                  // If temp is not null then cast it to int and return it,
                  // otherwise return 0
                  return temp == null ? 0 : (int)temp;
            }
            set { ViewState["DDLCount"] = value; }
      }
      private void CreateDropDownLists()
      {
            int a = Convert.ToInt32(TextBox4.Text);
            // This is just to set the count to a default value
            // You may possibly need to generate the count of dropdownlists
            // in some other manner, depending on your project
            //if (DDLCount == 0)
            DDLCount = a;   //i   have   to   ask   HOw   DDLCount   is   0
            // I   can   not   understand   it 
 

            for (int i = 0; i < DDLCount; i++)
            {
                  // Create the dropdownlists
                  DropDownList ddl = new DropDownList();
                  DropDownList dd2 = new DropDownList();
                  ddl.ID = "Text" + i;
                  dd2.ID = "Texts" + i;
                  LiteralControl l1 = new LiteralControl("<br></br>");
 
                  //ddl.Items.Add(new ListItem("TestText_" + i, "TestValue_" + i));
                  //ddl.Items.Add("anant");
                  //ddl.Items.Add("pratibha");
                  //ddl.Items.Add("rahul");
                  SqlConnection con1 = new SqlConnection("Data Source=ABC-0D30299B90A;Initial Catalog=JAPIT;Integrated Security=True");
                  con1.Open();
                  string st = "select   doe_name from   Doe_detail ";
                  SqlCommand cmd = new SqlCommand(st, con1);
                  SqlDataReader dr = cmd.ExecuteReader();
                  while (dr.Read())
                  {
                     ddl.Items.Add(dr.GetString(0).ToString());
 

                  }
                  con1.Close();
 
                  SqlConnection con2 = new SqlConnection("Data Source=ABC-0D30299B90A;Initial Catalog=JAPIT;Integrated Security=True");
                  con2.Open();
                  string std = "select   phone from   Doe_detail ";
                  SqlCommand cmd1 = new SqlCommand(std, con2);
                  SqlDataReader dr1 = cmd1.ExecuteReader();
                  while (dr1.Read())
                  {
                        dd2.Items.Add(dr1.GetString(0).ToString());
 

                  }
                  con2.Close();
                  
                  // Add it to the panel
                  Panel3.Controls.Add(ddl);
                  Panel3.Controls.Add(dd2);
 
            }
      }
 

 
   
      protected void TextBox4_TextChanged(object sender, EventArgs e)
      {
 
      }
      protected void Button1_Click(object sender, EventArgs e)
      {
            CreateDropDownLists();
 
      }
      protected void Button2_Click(object sender, EventArgs e)
      {
            string value = "";
            string ids = "";
            // Cycle through each dropdownlist
            for (int i = 0; i < DDLCount; i++)
            {
                  // Find the dropdownlist inside the Panel
                  DropDownList ddl = Panel3.FindControl("Text" + i) as DropDownList;
 
                  // Set the label to the SelectedValue of the dropdownlist
                  //Label1.Text += ddl.SelectedValue + " : ";
                  value = ddl.SelectedValue.ToString();
                  DropDownList dd2 = Panel3.FindControl("Texts" + i) as DropDownList;
 
                  // Set the label to the SelectedValue of the dropdownlist
                  //Label1.Text += ddl.SelectedValue + " : ";
                  ids = dd2.SelectedValue.ToString();
                  SqlConnection con = new SqlConnection("Data Source=ABC-0D30299B90A;Initial Catalog=JAPIT;Integrated Security=True");
 
                  con.Open();
 
                  SqlCommand cmd1 = new SqlCommand("insert into niitstud values('" + value + "','"+ids+"')", con);
                  cmd1.ExecuteNonQuery();
                  con.Close();
            }
      }
}