//ddlDept.OnSelectedIndexChanged and txtBookingDate_TextChanged,ddlbilltype.OnSelectedIndexChanged
 protected void txtBookingDate_TextChanged(object sender, EventArgs e)
 {
     BindInfoByDep(ddlDept.SelectedItem.Text);
     HideFieldsWhenRefund();
     if (hidID.Value == "0") //新增
     {
         txtInnerReferenceID.Text = svr.GetNextInnerReferenceID(
             ddlDept.SelectedItem.Text, txtBookingDate.Text, ddlBillType.SelectedValue);
     }
 }