json - jQuery ajax request from asmx web service -

i'm attempting request data http post asmx web service jquery's ajax. i've read numerous guides on how correctly no success. can determine, request failing:

$.ajax({     type: 'post',     url: "http://data.niassembly.gov.uk/organisations.asmx/getpartieslistcurrent_json",     contenttype: 'application/json; charset=utf-8',     data: json.stringify({}),     datatype: 'json',     success: function(data){         if (data.hasownproperty('d')){             msg = data.d;             } else {             msg = data;             }              alert(msg);     }     ,     error:function(){         alert('error');         } }); 

the json formatting correct , when save content local .json file function works. service has option i've read won't work in case.

try this:

$.ajax({    type: 'post',    //url: "http://data.niassembly.gov.uk/organisations.asmx/getpartieslistcurrent_json",    url: "http://data.niassembly.gov.uk/organisations_json.ashx?m=getpartieslistcurrent",    contenttype: 'application/json; charset=utf-8',    data: json.stringify({}),    datatype: 'jsonp',    success: function(data) {      alert(data.organisationslist.organisation[1].organisationname);      },    error: function() {      alert('error');    }  });

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>