My Dropdownlist always take the 1st value of database

Question

if (Session["User_Name"] == null)

{

Response.Redirect("Salon.aspx");

}

else

{

IEnumerator mc;

mc = Request.Cookies.AllKeys.GetEnumerator();

while (mc.MoveNext())

{

if (Request.Cookies[mc.Current.ToString()].HasKeys == true)

{

IEnumerator sc;

sc = Request.Cookies[mc.Current.ToString()].Value.GetEnumerator();

if (!Page.IsPostBack)

{

Wella.Visible = false;

Sebastian.Visible = false;

Nioxin.Visible = false;

illumina.Visible = false;

DropDownList1.AutoPostBack = true;

string Value = DropDownList1.SelectedValue;

lbUserName.Text = "WELCOME:: " + Session["User_Name"];

SqlConnection con = new SqlConnection(ConStr);

{

SqlCommand com = new SqlCommand("select User_Name,Company_Name from tblCompany where User_Name='" + Session["User_Name"] + "' ", con);

{

SqlDataAdapter da = new SqlDataAdapter(com);

DataSet ds = new DataSet();

da.Fill(ds);

DropDownList1.DataSource = ds;

DropDownList1.DataTextField = "Company_Name";

DropDownList1.DataValueField = "User_Name";

DropDownList1.DataBind();

DropDownList1.Items.Insert(0, new ListItem("---Select---", String.Empty));

DropDownList1.SelectedIndex = 0;

}

}

}

}

}

}