dropdownlist some code problems will come

Question

My recouvrement is when will selected dropdown list that value is stored in my textbox

this is my code """"::::

 

code 

 

protected void Button1_Click(object sender, EventArgs e)

{

try

{

string db = ConfigurationManager.ConnectionStrings["DDDB"].ConnectionString;

SqlConnection con = new SqlConnection(db);

SqlCommand cmd = new SqlCommand("select id, name,village from gridview ", con);

con.Open();

SqlDataReader rr = cmd.ExecuteReader();

DropDown1.DataTextField = "name";

DropDown1.DataValueField = "id";

DropDown1.DataSource = rr;

DropDown1.DataBind();

con.Close();

Lbl.Text = "connected";

TextBox1.Text = DropDown1.SelectedValue;

}

catch (Exception ex)

{

Lbl.Text = ex.Message;

// Response.Write("<script>alert('" + ex + "')</script>");

}

}