I am trying to create a smart object which reads from, and updates data in a custom SQL application database.  The problem is I can't figure out how to accomplish this task. 

From looking around, I determined that the correct thing to do was to create a new SmartBox Service (under the Management Console in the Workspace).  I tried adding a new Service Instance to the SmartBox configuration.  When I click Add, I am prompted for the database connection string along with some other fields.  I used the connection string from the default SmartBox instance and replaced it with my database name (they are on the same server).  No matter what I try, I can not get the wizard to connect to the database.  Since that connection fails, I cannot create the instance.  I also tried creating a connection in the Server Explorer in Visual Studio and then using that same connection string to create the Service Instance.  This didn't work, either. 

 Any suggestions?  Am I even in the right ballpark to accomplish this?

Thanks in advance.