$.ajax submit with json - issues

$.ajax submit with json - issues

Hi Im trying to make an HTTP Post to a WCF service and I keep either getting a 500 Internal service error saying that the data is "Raw" or a 403 returned. Here is what Im attempting to  use, if this looks ok I can bring up the 403 issue with the third party. Does this look correct?

//validation stuff
submitHandler: function(form) {
var dataToBeSent = $("form").serialize();
$.ajax({
                url: form.action,
                type: "POST",
                data: dataToBeSent,
                dataType: "json",
                processData: true,
                contentType: "application/json; charset=utf-8",
                timeout: 10000
               
               
                });
            return false;
           
           },

//validation stuff

Thanks!