protected void Page_Load(object sender, EventArgs e)
 {
     if (Session["LogIn"] == null)
     {
         Response.Redirect("LogInUI.aspx");
     }
     if (!IsPostBack)
     {
         companyDropDownList.DataSource     = stockInManager.CompanyDropDownList();
         companyDropDownList.DataValueField = "Id";
         companyDropDownList.DataTextField  = "Name";
         companyDropDownList.DataBind();
         companyDropDownList.Items.Insert(0, new ListItem("--Select Company--", "0"));
     }
 }