jQuery Validate Group

[donboe]

I have three select boxes for populating the DOB. All three are required but I would like to show one message. I have been searching on Google and found several topics about this and all mentioned to use groups which I tried

groups: {    
  DateOfBirth: "dob_day dob_month dob_year"  
},  
errorPlacement: function(error, element) {    
    if (element.attr("name") == "dob_day" || element.attr("name") == "dob_month" || element.attr("name") == "dob_year" ) {      
        error.insertAfter("#lastname");    
    } else {      
        error.insertAfter(element);    
    }  
}

Bur for me the errorPlacement, as in this example, is not an option because I used CSS for creating a custom error message/placement as you can see below:

#registration_form label {
  padding: .8rem .6rem;
  position: absolute !important;
  top: -3rem;
  right: 0;
  z-index: 10;
  -webkit-transition: all 2s ease-out;
  transition: all 2s ease-out;
  display: none;
  background-color:transparent;
  background-color:rgba(0,0,0,0.9);
  border-radius: 4px;
  -moz-border-radius: 4px;
  -webkit-border-radius: 4px;
  color: #FFF;
}

#registration_form label:after {
  content: "";
  position: absolute;
  bottom: -10px;
  left: 45%;
  border-style: solid;
  border-width: 10px 10px 0;
  border-color: #000000 transparent;
  display: block;
  width: 0;
  z-index: 10;
}

How should I adjust the given groups example so that there will be just one error message for the three select boxes at the in CSS created location.

Thank you in advance