I want to pass label/value pair in Ajax .POST but cannot find any solution. Any help please.

        $.ajax({
            url:"allfields.php",
            type:"POST",
    //      dataType:"json",
            data: $("#frmRequest").serialize(),
            success: function(msg){
                alert("Form Submitted: "+ msg);
                return msg;

              },
             error: function() {
            alert('Error occured');
             }
        });