retrieve datas to textbox from database?

 protected void Page_Load(object sender, EventArgs e)
    {
     try
        {
            string selectSQL = "select name,gender,Designation,Deptt,Location,dob,emailid from empbirth where userid='" + txtempcode.Text + "'";
            SqlCommand cmd = new SqlCommand(selectSQL, cnn);
            SqlDataReader dr;
            cnn.Open();
            dr = cmd.ExecuteReader();
            
            if (dr.Read())
            {
                txtname.Text = dr[0].ToString();
                txtgender.Text = dr[1].ToString();
                txtdesignation.Text = dr[2].ToString();
                txtdepartment.Text = dr[3].ToString();
                txtlocation.Text = dr[4].ToString();
                txtdob.Text = dr[5].ToString();
                txtEid.Text = dr[6].ToString();

            }
        }
        catch (Exception ex)
        {
            Response.Write(ex.ToString());
        }
}