aspnet 事务

http://www.springframework.net/docs/1.3.0/reference/html/transaction.html
http://blog.csdn.net/shaily/archive/2010/03/17/5388912.aspx
http://msdn.microsoft.com/en-us/library/ms973865.aspx
http://people.apache.org/~hammett/articles/dotnettransactions.html