Asynchronous Web Service Call Fails

[nirk]

Hi
I created a webservice with a simple we method to increment a number passed from the client(a console app) .
Then i call this web service method asynchronus mode from the client.
I create a callback function and call EndXXX(XXX denotes the function name) in the callback function.
But the function call never ends. means the web service is not working in async mode
I have added the web refernce properly because i was able to succesfully call the same function in synchronous mode

Where am i going wrong

Thanks in advance
Nirk