1. A method for operating a service level execution environment (SLEE) in a service creation switch coupled to a media gateway, the method comprising: providing a SLEE having a plurality of layers providing call service functions carried out by the service creation switch, the plurality of layers of the SLEE including an application layer and a media server layer, the application layer including functionality that manages state information for calls serviced by the service creation switch, and the media server layer including functionality that provides enhanced services that include the playing of a voice prompt, wherein the SLEE is generated by: i) compiling scripts to be executed in the SLEE, wherein each given script includes identification data that identifies a layer of the SLEE as well as program code defining call service functions provided by the layer of the SLEE identified by the identification data of the given script, ii) storing the compiled scripts as part of dynamic link libraries corresponding to the plurality of layers of the SLEE, wherein the compiled scripts of the dynamic link libraries provide call service functions defined by the program code of the compiled scripts, and iii) for each given one of the plurality of layers of the SLEE, dynamically loading at least one dynamic link library corresponding to the given layer for invoking call service functions carried out by the given layer; wherein the functionality of the media server layer of the SLEE includes at least one dynamic link library that provides enhanced services that include the playing of a voice prompt in accordance with the program code of at least one script embodied therein.