calling WCF using AJAX and jquery

$.ajax({
type: "POST",
dataType: "json",
url: "../Service1.svc/myservice",
data: '{ 'field_name=" '+'value'+'",'....}', //for passing json formatted input(argument) to method 'myservice'
contentType: "application/json; charset=utf-8",
success: function (r) {
alert(eval('(' + r.d.toString() + ')')); //your output also in json format only
},
error: function (e) {
alert("your error message");
}

});

In above code you can call WCF using ajax with json formatted input and json formatted output