In which layer would you implement transactions using asp.NET TransactionScope?

I have a service, business and data access layer. In which l开发者_StackOverflow社区ayer should I implement transactions using asp.NET transactionscope? Also, is nesting Transactions a good thing because I had problems with that?

Transaction Scope is part of .net not specific to asp.net

We would place the tansaction scope in the business layer. The service layer is more of a facade. If something requires a transaction it should be within a single business operation.