Request Format is invalid

Request Format is invalid

Hi,
 
I have JSONP Web service called from Javascript. This works fine for me if Web service and the code from where i am calling web service are on same machine, but if web service is on another domain then i get 'Request format is invalid' error from my web service.  Both machines are on same domain.
 
I am really struggling from this issue. Request you to provide details on this.
 
Thanks.