谢谢！

// -----------------------------------------------
// CHECK SINGLE CHECKBox
// -----------------------------------------------
$('.mcCbxrequired').each(function() {
    var mcCbxCheck = $(this);
    if(mcCbxCheck.is(':checked')) {
        alert('checked');
        // do something here ...
    }
    else{
        alert('not checked');
        return false;
    }
});