Working

Once the concerned ISAPI DLL is loaded into memory, a worker thread starts running to manage the extension. The first function to be called is the entry point DLLMain function. On completion, the server makes a call to GetExtensionVersion function to perform two tasks - to exchange version information and to get a short text description of the extension. The server then calls the HttpExtensionProc function passing a copy of the ECB's pointer to start the actual ISAPI extension. This function makes writing data back to the client possible.