asp.net2.0实现文件上传,控制上传文件大小,类型

    protected void Button1_Click(object sender, EventArgs e)
    {
        if (FileUpload1.HasFile)
        {

            Label2.Text = FileUpload1.FileName;
            Label3.Text = FileUpload1.PostedFile.ContentLength.ToString() + "字节";
            Label4.Text = FileUpload1.PostedFile.FileName;
            //获得扩展名
            string extension = System.IO.Path.GetExtension(FileUpload1.FileName);
            if (extension == ".rar" || extension == ".doc" || extension == ".xls")
            {

                if (FileUpload1.PostedFile.ContentLength < 10000000)//文件小于10M
                {
                    FileUpload1.SaveAs(Server.MapPath("~/upLoad/" + FileUpload1.FileName));
                    Label1.Text = "恭喜你，上传成功!";
                }
                else
                {
                    Label1.Text = "上传失败，不是管理员，上传文件不能大于10M！";
                }
            }
            else
                Label1.Text = "上传失败，只能上传扩展名是rar、doc、xls的文件！";
        }
        else
        {
            Label1.Text = "上传失败，或没指定正确的文件!";
        }
    }