how to set path to the scriptreference in ScriptManager

[lovedotnet]

hi...i need to give the path of the webservice(which is running in another machine) in the serviceReference....if the webservice is in our solution then we use the following code asp:servicereference path="~/WebServices/MySampleService.asmx" but now my webservice is in another machine which is published.... i have written code like this... asp:servicereference path="http://12.18.15.17/WebServices/MySampleService.asmx" but the javascript throws error "Mysampleservice" is undefined... ..can anyone suggest me how to fix this?