ASP服务器变量无法在本地IIS上运行

I'm working on a simple ASP.Net page (handler, actually) where I check the value of the LOGON_USER server variable. This works using Visual Studio's built-in web server and it works in other sites deployed to the live intranet site. But it doesn't work on the IIS instance on my local XP machine. How can I fix it, or what's going on if I can't?I'm working on a simple ASP.Net page (handler,