I am using a layered architecture with the Entity Framework. Here's What I came up with till now (All the projects Except UI are class library):

• Entities: The POCO Entities. Completely persistence ignorant. No Reference to other projects. Generated by Microsoft's ADO.Net POCO Entity Generator.

• DAL: The EDMX (Entity Model) file with the context class. (t4 generated). References: Entities

• BLL: Business Logic Layer. Will implement repository pattern on this layer. References: Entities, DAL. This is where the objectcontext gets populated: var ctx=new DAL.MyDBEntities();

• UI: The presentation layer: ASP.NET website. References: Entities, BLL + a connection string entry to entities in the config file (question #2).

Now my three questions:

1. Is my layer discintion approach correct?

2. In my UI, I access BLL as follows:
   var customerRep = new BLL.CustomerRepository();
var Customer = customerRep.GetByID(myCustomerID);

   The problem is that I have to define the entities connection string in my UI's web.config/app.config otherwise I get a runtime exception. IS defining the entities connectionstring in UI spoils the layers' distinction? Or is it accesptible in a muli layered architecture.

3. Should I take any additional steps to perform chage tracking, lazy loading, etc (by etc I mean the features that Entity Framework covers in a conventional, 1 project, non POCO code generation)?

Thanks and apologies for the lengthy question.