protected void Page_Load(object sender, EventArgs e)
        {
            Session["Local"] = "调拨单作业";
            if (Session["LoginName"] == null)
            {
                PageUtil.showToast(this, "未获取到你的登陆状态,请退出系统重新登录!");
                return;
            }
            else
                user = Session["LoginName"].ToString();

            if (!IsPostBack)
            {
                DataSet ds_Invoice_no = invoiceDC.getExchangeInvoice_no();
              
                if (ds_Invoice_no != null)
                {
                    DropDownList_invoice_no.DataSource = ds_Invoice_no.Tables[0].DefaultView;
                    DropDownList_invoice_no.DataValueField = "invoice_no";
                    DropDownList_invoice_no.DataTextField = "invoice_no";
                    DropDownList_invoice_no.DataBind();
                }           
                DropDownList_invoice_no.Items.Insert(0, "--选择调拨单号--");
               
            }
        }