Calling a C# method using jQuery on the client side

[OperationContract]
        [WebInvoke(Method = "POST")]
        public void DeleteRec(string ID)
        {
            DelUser(Convert.ToInt32(ID));
        }

function DeleteMessage() {            
            var ID = $('[id$="hdnUserId"]').val();
            var url = '<%=ResolveUrl("~/WebMethods.svc/DeleteRec")%&  gt;';            
            $.ajax({
                type: "POST",
                url: url,
                contentType: "application/json; charset=utf-8",
                data: '{"ID":"' + ID + '"}',
                dataType: "json",
                success: function (response) {
                    document.location.href = '<%= ResolveUrl("~/Test1.aspx")%>';
                },
                error: function (xhr, ajaxOptions, thrownError) {
                }
            });
        }