  using System;
  using System.Collections.Generic;
  using System.Web;
  using System.Web.UI;
  using System.Web.UI.WebControls;
  
  public partial class main : System.Web.UI.Page
  {
      protected void Page_Load(object sender, EventArgs e)
      {
          if (【Session】["user"]!= null)
              Response.Write("欢迎" + Session["user"].ToString());
          else
              Response.【Redirect】("login.aspx");
      }
  }
