asp.net - jQuery ajax POST error for wcf sevice -

this cross-domain ajax request:

$.ajax({             type: "post",             datatype: "jsonp",             contenttype: "application/jsonp",             data: '{"username":"newuser","password":"pwd"}',             crossdomain: true,             async: false,             url: "http://xxx.xx.xx.xx/myservice/sampleservice.svc/getdata",             jsonpcallback: function (jsondata) {                 console.log(jsondata);                 alert('hi');             },             complete: function (request, textstatus) {                  alert(request.responsetext);                 alert(textstatus);             },             error: function (request, textstatus, errorthrown) {                 alert(textstatus);             }         }); 

this wcf rest service's method:

namespace sampleservicerestapi { [aspnetcompatibilityrequirements(requirementsmode = aspnetcompatibilityrequirementsmode.allowed)] [servicebehavior(instancecontextmode = instancecontextmode.single)] public class sampleservice : isampleservice  {    ...    public string getdata(userdata userdata)    {       string response = "hi_" + userdata.username;       return response;    }    ... } 

interface:

    [webinvoke(method = "post", requestformat = webmessageformat.json, responseformat = webmessageformat.json, bodystyle = webmessagebodystyle.bare, uritemplate = "getdata")]     [operationcontract]     string getdata(userdata userdata); 

datacontract:

[datacontract] public class userdata {     [datamember]     public string username { get; set; }      [datamember]     public string password { get; set; } } 

and thepart of web.config:

<system.web>    <compilation debug="true" targetframework="4.0"/>    <pages controlrenderingcompatibilityversion="3.5" clientidmode="autoid"/>     </system.web> <system.servicemodel> <standardendpoints>   <webscriptendpoint>     <standardendpoint name="" crossdomainscriptaccessenabled="true"/>   </webscriptendpoint> </standardendpoints> <servicehostingenvironment multiplesitebindingsenabled="true" aspnetcompatibilityenabled="true" >   <serviceactivations>     <add factory="system.servicemodel.activation.servicehostfactory" relativeaddress="sampleservice.svc" service="sampleservicerestapi.sampleservice"/>   </serviceactivations> </servicehostingenvironment> <services>   <service behaviorconfiguration="servicebehaviour" name="sampleservicerestapi.sampleservice">     <endpoint address="" behaviorconfiguration="web" binding="webhttpbinding"       bindingconfiguration="webwinbinding" contract="sampleservicerestapi.isampleservice" />           </service>   <!--<service behaviorconfiguration="metadatabehavior" name="myservice">     <endpoint address="mex" binding="mexhttpbinding" contract="imetadataexchange"/>   </service>--> </services> <behaviors>   <endpointbehaviors>     <behavior name="web">       <webhttp/>     </behavior>   </endpointbehaviors>   <servicebehaviors>     <behavior name="servicebehaviour">       <servicemetadata httpgetenabled="true" />       <servicedebug includeexceptiondetailinfaults="true"  />     </behavior>     <behavior name="">       <servicemetadata httpgetenabled="true" />       <servicedebug includeexceptiondetailinfaults="true" />     </behavior>   </servicebehaviors> </behaviors> <bindings>   <webhttpbinding>     <binding name="webwinbinding" maxbuffersize="2147483647" crossdomainscriptaccessenabled="true" maxreceivedmessagesize="2147483647">        <readerquotas maxarraylength="100000" maxstringcontentlength="2147483647" />     </binding>   </webhttpbinding> </bindings> </system.servicemodel>   <!--<system.web.extensions>   <scripting>   <webservices>     <jsonserialization maxjsonlength="2147483644"/>     <protocols>       <add name="httppost"/>            <add name="httppostlocalhost"/>        </protocols>         </webservices> </scripting> </system.web.extensions>--> <system.webserver> <modules runallmanagedmodulesforallrequests="true"/>   <httpprotocol>     <customheaders>       <add name="access-control-allow-origin" value="*" />       <add name="access-control-allow-headers" value="content-type" />     </customheaders>   </httpprotocol> </system.webserver> <appsettings>   <add key="errorcodefile" value="~/app_data/errorcode.txt"/> </appsettings> 

the error got in firebug:

"networkerror: 500 internal server error - http://173.161.176.229/myservice/sampleservice.svc/getdata?callback=undefined&{%22username%22:%22newuser%22,%22password%22:%22pwd%22}&_=1369120080493"

the 500 error indicates somethings wrong on serverside. should examine going wrong there. possible have wcf part. perharps helps: http://msdn.microsoft.com/en-us/library/ms732023.aspx