How to add controls dynamically in asp.net

using  System;
using  System.Collections.Generic;
using  System.Linq;
using  System.Web;
using  System.Web.UI;
using  System.Web.UI.WebControls;
using  System.Xml.Serialization;
using  System.IO;
using  System.Runtime.Serialization;
using  System.Xml;
using  System.Web.Security;
public   partial   class  Default2 : System.Web.UI.Page
{
     protected   void  Page_Load( object  sender, EventArgs e)
    {

    }
     protected   override   void  LoadViewState( object  savedState)
    {
         base .LoadViewState(savedState);
        Panel1.Controls.Clear();
         int  rows  =   int .Parse(ViewState[ " Rows " ].ToString());
         if  (ViewState[ " Rows " ]  !=   null )
        {
            Table tb  =   new  Table();
            tb.ID  =   " AllRows " ;
            TableRow tr  =   null ;
             for  ( int  r  =   0 ; r  <  rows; r ++ )
            {
                tr  =   new  TableRow();
                 for  ( int  c  =   0 ; c  <   3 ; c ++ )
                {
                    TableCell tc  =   new  TableCell();
                    tc.ID  =   " tc_ "   +  r.ToString()  +   " _ "   +  c.ToString();
                    tr.Cells.Add(tc);
                }
                TextBox txt  =   new  TextBox();
                txt.ID  =   " TextBox_ "   +  r.ToString()  +   " _0 " ;
                tr.Cells[ 0 ].Controls.Add(txt);

                Button bt  =   new  Button();
                bt.ID  =   " bt_ "   +  r.ToString()  +   " _Del " ;
                bt.CommandArgument  =  r.ToString();
                bt.Text  =   " Delete current row " ;
                bt.Click  +=   new  EventHandler(bt_Click);
                tr.Cells[ 1 ].Controls.Add(bt);
                tb.Rows.Add(tr);
            }
            Panel1.Controls.Add(tb);
             //  this.Panel1.Controls.Add(tb);
        }
    }

     void  bt_Click( object  sender, EventArgs e)
    {
        Button bttemp  =  sender  as  Button;
        Table result  =  Panel1.FindControl( " AllRows " )  as  Table;
        result.Rows.RemoveAt( int .Parse(bttemp.CommandArgument));
         int  rows  =  ViewState[ " Rows " ]  ==   null   ?   1  :  int .Parse(ViewState[ " Rows " ].ToString());
        ViewState[ " Rows " ]  =  (rows  -   1 ).ToString();      
    }
     protected   void  Button1_Click( object  sender, EventArgs e)
    {
        Panel1.Controls.Clear();
         int  rows  =  ViewState[ " Rows " ]  ==   null   ?   1  :  int .Parse(ViewState[ " Rows " ].ToString())  +   1 ;
        Table tb  =   new  Table();
        tb.ID  =   " AllRows " ;
        TableRow tr  =   null ;
         for  ( int  r  =   0 ; r  <  rows; r ++ )
        {
            tr  =   new  TableRow();
             for  ( int  c  =   0 ; c  <   3 ; c ++ )
            {
                TableCell tc  =   new  TableCell();
                tc.ID  =   " tc_ "   +  r.ToString()  +   " _ "   +  c.ToString();
                tr.Cells.Add(tc);
            }
            TextBox txt  =   new  TextBox();
            txt.ID  =   " TextBox_ "   +  r.ToString()  +   " _0 " ;
            tr.Cells[ 0 ].Controls.Add(txt);

            Button bt  =   new  Button();
            bt.ID  =   " bt_ "   +  r.ToString()  +   " _Del " ;
            bt.Click  +=   new  EventHandler(bt_Click);
            bt.CommandArgument  =  r.ToString();
            bt.Text  =   " Delete current row " ;

            tr.Cells[ 1 ].Controls.Add(bt);
            tb.Rows.Add(tr);
        }
        Panel1.Controls.Add(tb);
        ViewState[ " Rows " ]  =  rows.ToString();
    }
     protected   void  Button2_Click( object  sender, EventArgs e)
    {
        Table result  =  Panel1.FindControl( " AllRows " )  as  Table;
         foreach  (TableRow tr  in  result.Rows)
        {
            Response.Write((tr.Cells[ 0 ].Controls[ 0 ]  as  TextBox).Text + " <br> " );
        }
    }
}
 

//

< form  id ="form1"  runat ="server" >
     < div >   
         < asp:Panel  ID ="Panel1"  runat ="server" >
         </ asp:Panel >
         < asp:Button  ID ="Button1"  runat ="server"  onclick ="Button1_Click"  Text ="Add Row"  
            Width ="75px"   />   
         < asp:Button  ID ="Button2"  runat ="server"  Text ="Results"  
            onclick ="Button2_Click"   />    
     </ div >
     </ form >