How to call webservice through JQuery

Question

 Hi all,

<script type = "text/javascript">

    function DisplayMessageCall() {

        var pageUrl = '<%=ResolveUrl("http://192.168.141.43//MCHWebservice//CallService.asmx")%>'

        $.ajax({

            type: "Get",

            url: pageUrl + "/TestHTML",

            data: '{}',

            contentType: "application/json; charset=utf-8",

            dataType: "json",

            success: OnSuccessCall,

            error: OnErrorCall

        });

      }

    function OnSuccessCall() {

        alert("success");

    }

    function OnErrorCall(response) {

        alert("Failure");

            }

Here,

I am trying to call TestHTML method, which returns the values in the format of XML.

and i am trying to run the above code but everytime i am getting failure message.