protected void uiLinkButtonOK_Click(object sender, EventArgs e)
        {
            Envelops envelop = new Envelops();
            if (CurrentEnvelop == null)
            {
                envelop.AddNew();
                envelop.UploadDate = DateTime.Now;
            }
            else
                envelop = CurrentEnvelop;

            envelop.ColorID = Convert.ToInt32(uiDropDownListColor.SelectedValue);
            envelop.DimensionID = Convert.ToInt32(uiDropDownListDim.SelectedValue);
            double price = 0;
            double.TryParse(uiTextBoxPrice.Text, out price);
            envelop.Price = price;

            if (uiFileUploadImage.HasFile)
            {
                string filepath = "/images/Envelop/" + DateTime.Now.ToString("ddMMyyyyhhmmss") + "_" + uiFileUploadImage.FileName;
                uiFileUploadImage.SaveAs(Server.MapPath("~" + filepath));
                envelop.ImagePath = filepath;
            }
            envelop.Save();
            ClearFields();
            CurrentEnvelop = null;
            uiPanelEditCat.Visible = false;
            uiPanelAllCats.Visible = true;
            BindCats();
        }