I'm having a problem getting our Web Service DLL to 'recognize' the
middle-tier DLL when each resides on different machines. Here's our general

We have a WinForm front-end, a web service running on IIS that 'channels'
user requests through to the middle-tier [and then on to SQL Server, and
then back].

So if I'm in Screen 'A' and want to retrieve record 'XYZ', the winform sends
up a dataset to the web service. The dataset contains info on what the user
wants to run. So I'll create a dataset like so...

DsRemoteInfo: "Screen A", "RetrieveRecord", "XYZ"

and then do a ....WebService.Service1 oService = new WebService.Service1();
oService1.URL = <configured URL>
DataSet DsReturn = oService.PerformService(DsRemoteInfo)

The Web Service function 'perform service' takes the Dataset and passes it
on to an application manager, which is sort of a 'face' module for the
middle-tier. The appropriate function in the middle tier is called, and
then any resulting data is passed back.

That all works fine...so long as the Web Service DLL/assembly and the middle
tier assemblies/DLLs are on the same machine. However, we realize that most
client installs will have the Web Service on a different machine/server than
the machine/server for the middle-tier. That's where we've hit a wall.

We know that we have to use a Web Config file for the Web Service to locate
the assembly for the middle-tier. We've also read some docs from MSDN on
Codebases/probing, and we realize that the assembly must be strongly
defined/public [as opposed to private].

However, when we try the 'recommended' approach, we get errors when the Web
Service DLL tries to 'access' any function in the middle tier. We're able
to instantiate the primary middle-tier DLL from within the Web Service, but
when we try to access any function, it fails.

Sorry for the lengthy post, but I wanted to fully describe what we're trying
to do. Does anyone have any detailed advice on how to accomplish this? Are
there any web sites with FAQs that describe how to do this?