protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                GetLoadedDropDownlists();


                thanaDropDownList.DataSource = centerManager.GeTthanaAccordingToDistrictName(int.Parse(districtDropDownList.SelectedValue.ToString()));

                thanaDropDownList.DataTextField  = "Name";
                thanaDropDownList.DataValueField = "Id";

                thanaDropDownList.DataBind();
            }
        }
        public void GetLoadedThanaDropDownList()
        {
            int id = Convert.ToInt16(districtDropDownList.SelectedValue);

            thanaDropDownList.DataSource     = centerManager.GeTthanaAccordingToDistrictName(id);
            thanaDropDownList.DataValueField = "Id";
            thanaDropDownList.DataTextField  = "Name";
            thanaDropDownList.DataBind();
        }