protected void btn_Send_Click(object sender, EventArgs e)
        {
            Model1      ctx             = new Model1();
            Department  d               = ctx.Departments.Where(x => x.DeptName == lab_dept.Text).First();
            string      CollectionPoint = d.CollectionPoint;
            string      a               = Session["sign"].ToString();
            User        c               = ctx.Users.Where(x => x.UserName == a).First();
            string      Sender          = c.Email;
            List <User> receiver        = ctx.Users.Where(x => x.Role == "StoreClerk").ToList();

            string[] receive = new string[receiver.Count()];
            for (int i = 0; i < receiver.Count(); i++)
            {
                receive[i] = receiver[i].Email.ToString();
            }
            string Password = "******";

            Session["Title"]    = "CollectionPoint change Notification";
            Session["content"]  = Session["sign"].ToString() + ", who is from " + lab_dept.Text + " has changed the CollectionPoint, the new CollectionPoint is " + CollectionPoint + " .";
            lab_dept.Text       = SendEmail.sendEmail(Sender, Password, Session["Title"].ToString(), Session["content"].ToString(), receive);
            Session["Title"]    = "";
            Session["content"]  = "";
            Lab_successful.Text = "Email sent successful";
        }