ASP.Net DropDownList Selected Item is lost and default item is inserted in database on button click

hi 

i bind dropdownlist in my page

these ara my code

  protected void Page_Load(object sender, EventArgs e)
    {
        BindDropDownList(DDL1, "city1", "name", "ID");
    

        DDL1.Items.Insert(0, new ListItem("select city", "0"));

    }

andSP

LTER procedure [dbo].[city1]

as
begin
select id,Name
from city
end

and design code

 <asp:DropDownList ID="DDL2" runat="server" CssClass="daddsd">

            </asp:DropDownList>

and here is imagebutton code that when click on it update data into table

 protected void ImageButton_Click1(object sender, ImageClickEventArgs e)
    {
        string data = Server.UrlDecode(Request.QueryString["BehCode2"]);
            SqlCommand _cmd = new SqlCommand("insertinfo", _cn);
            _cmd.CommandType = CommandType.StoredProcedure;
            _cn.Open();

            _cmd.Parameters.AddWithValue("@Name", txtstore.Text);
            _cmd.Parameters.AddWithValue("@Ownername", Txtname.Text);
            _cmd.Parameters.AddWithValue("@Description", CKEditorControl1.Text);
            _cmd.Parameters.AddWithValue("@address", Txtadd.Text);
            _cmd.Parameters.AddWithValue("@City", DDL1.SelectedItem.Text);
           
            _cmd.Parameters.AddWithValue("@behcode", data);
          
            _cmd.ExecuteNonQuery();

            _cn.Close();
       

here when i click on button it insert all data into table but it didn't insert my selected item from dropdownlist it insert select city that i define in page_load

 DDL1.Items.Insert(0, new ListItem("select city", "0"));

and when i delete this code from page load it insert in table first row of my table it didn't insert my selected item from dropdown list

Thanks