Getting some problems

I am trying to call a web service synchronously. I receive 5-6 records. If I request for more recordes it gives timeout problem. Then I tried asynchronous method with callback.
Now in Callback method if i try to use any field of webform class it doesnt work. Similary if I try to use while loop to check when operation is completed through Isynch.Iscompleted property. It start running for infinity.

I need help My email is khalidj06@yahoo.com

Any positive response will be highly appreciated.