As we know ajax calls will not work for cross domain request. Here what i guess this is the cross domain issue what you are facing.
Like if your application is run as localhost then the service also should be called as localhost.
Same for IP address also, if you will running the application in localhost but trying to fetch the service by giving IP address it will not work.
Please have alook into the below link and please let me know if this solves your issue :-
http://stackoverflow.com/questions/13480652/jquery-ajax-call-to-c-sharp-web-service-error[
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Hope this will be helpful for you.