db Access problem

[justSteve]

I'm working with a .sln that has 2 projects...one has db connectivity, the other is intended to call methods of the db-connected project. This isn't a formal 'DAL' situation but it's along those lines - 2 projects; one for data access, one for displaying data.

The class in the UI project instantiates an object in the Data project:
private MyData.MyDataProvider emsData = new MyData.MyDataProvider();

and then calls methods via:
string customerList = emsData.GetCustomerList();

The process works as long as I define a connection string in the UI App.config file...but I think I shouldn't have to carry that information in the UI project. From my perspective...all i'm doing is calling a method in a referenced project and db connectivity is up to _that project...not the UI project.

As soon as I remove reference from UI I get a 'Object Reference not set to an instance of an object.'

I'm using the Enterprise Library Data Block...the error is occurring in:
Database db = DatabaseFactory.CreateDatabase();

The question is why that method wants to refer back to the calling method for the database connection string. If I call from within the data project stuff works. I thought separating responsibility as 'a good thing'.

many thankx for any thoughts.