Load Testing in VS 2010

I am performing a webtest containing 3 pages once of which is a Silverlight page and a Controller page (every page is invoked from controller page and again the control is given back to Controller page).

When the 1st link id clicked it generates one ID that has to be carried forward in every transaction till the completion of the transaction.

The 1st page is a Silverlight page it interacts thorough WCF services to do the transaction.while submitting A request through Silver light the WCF service generates a ID but since the data from the service is returned in 开发者_StackOverflow社区XML form, the entire output of the wcfservice if treated as a string data of which is hardcoded which is found at the time of recording.

So, After coming back from the 1st page (silverlight) to the Controller page it is always coming with the same ID which is stored as a string in the service in the recorded test. Since I am not getting the PROPER ID I am not able to move forward to other pages.

Actually, according to me system is not detecting the data returned from a WCF web service as a dynamic one and instead treating it as a hardcoded string.

How to resolve it, please help.

Some errors of Load test are written below:

Extraction Rule Error   ExtractValues event 139 No hidden fields were found in the response.    
Exception   WebTestException    84  There is no context parameter with the name '$HIDDEN1.ConfiguratorTracker$hdnWorkFlowGuid' in the WebTestContext    

Make sure you've created an Extraction Rule that is based on the Text Response and not a hidden field. You might want to take a look at a RegEx Extraction Rule.