E:\asp.net\我们做的网站\flashfz\qruanadmin\addcpjs.aspx.cs(15): 找不到类型或命名空间名称“Bestcomy”(是否缺少 using 指令或程序集引用？)

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.IO;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Xml;
using System.Data.OleDb;
using Bestcomy.Web.Controls.Upload;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
这里有什么问题吗?

帮个忙啊,急

怎么引?