我怎样才能发现*我的网站被黑了怎么办？我如何找到网站漏洞？

One of my custom developed ASP.NET sites was hacked today: "Hacked By Swan (Please Stop Wars !.. )" It is using ASP.NET and SQL Server 2005 and IIS 6.0 and Windows 2003 server. I am not using Ajax and I think I am using stored procedures everywhere I am connecting to the database so I dont think it is sites was ha