Text to Speech

Hello - I found this article very helpful, but am having problems when I publish it on the web server (Windows 2003 IIS) - I get the same message - i.e. The type or namespace name ‘SpeechSynthesizer’ could not be found (are you missing a using directive or an assembly reference?) on the server in the Event Viewer. Is there special configuration or files required on the server before you can publish the speech to text files? Any help would be appreciated.