[jQuery] [Validation]How to make two field check output one message?

[jQuery] [Validation]How to make two field check output one message?


Hi,
Some question on the config of validation plugins.
Suppose there are #fromDate and #toDate fields (using ui.datepicker).
I have added these custom rules
            jQuery.validator.addMethod("afterFromDate" ,function(value,
element, targetId){
                var fromDate = $("#"+targetId).datepicker("getDate");
                var toDate = $(element).datepicker("getDate");
                if(toDate && fromDate && fromDate > toDate){
                    return false;
                }
                return true;
            }, "Please input correct date range");
            jQuery.validator.addMethod("beforeToDate" ,function(value, element,
targetId){
                var fromDate = $(element).datepicker("getDate");
                var toDate = $("#"+targetId).datepicker("getDate");
                if(toDate && fromDate && fromDate > toDate){
                    return false;
                }
                return true;
            }, "Please input correct date range");
And config like
$("#form").validate({
rules:{
    'fromDate': { beforeToDate:'fromDate' },
    'toDate: { afterFromDate:'toDate' },
}
})
It will output two messages of 'Please input correct date range'.
How can I make it only ouput single one?