ih ave one table called codemster in that table i have two fileds codetype and codedesc codetype is ...

Hi Narasiman,


When you choose any codetype from the dropdownlist then its corresponding codedesc will be shown in the textbox.



Try this...

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>





   


   

   

   
   

            onselectedindexchanged="DropDownList1_SelectedIndexChanged">
   

   
   

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;
public partial class _Default : System.Web.UI.Page
{
    string strConnString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
    string str;
    SqlCommand com;
    protected void Page_Load(object sender, EventArgs e)
    {
        DropDownList1.AutoPostBack = true;
        SqlConnection con = new SqlConnection(strConnString);

        if (!IsPostBack)
        {
            DropDownList1.Items.Add("Choose codetype");
            con.Open();
            str = "select * from codemaster";
            com = new SqlCommand(str, con);
            SqlDataReader reader = com.ExecuteReader();
            while (reader.Read())
            {
                DropDownList1.Items.Add(reader["codetype"].ToString());
            }
            reader.Close();
            con.Close();
        }
    }
    protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        SqlConnection con = new SqlConnection(strConnString);
        con.Open();
        str = "select * from codemaster  where codetype='" + DropDownList1.SelectedItem.Text + "'";
        com = new SqlCommand(str, con);
        SqlDataReader reader = com.ExecuteReader();
        while (reader.Read())
        {
            TextBox1.Text = reader["codedesc"].ToString();
           
        }
        reader.Close();
        con.Close();
    }
}



Thanks