jQuery validate across multiple fields -

i have 3 input fields ask number of people, , of them how many adults , how many children. trying use jquery validate plugin add custom method children + adults = number of people

this validation call

$("#form2").validate({     errorelement: "span",         rules: {         attendees: {              required: true,              digits: true         },                       adults: {              required: true,              digits: true         },                       children: {              required: true,              digits: true         }     },     messages: {         attendees: "enter number of persons (including yourself)",          adults: "enter number of adults",          children: "enter number of childern"                     }                }); 

i looked @ group feature , addmetod of validate plugin seems crafted 1 element in mind. ideas ?

follow the documentation creating custom method/rule. here, call totalcheck, can name wish.

$.validator.addmethod('totalcheck', function(value, element, params) {     var field_1 = $('input[name="' + params[0] + '"]').val(),         field_2 = $('input[name="' + params[1] + '"]').val();     return parseint(value) === parseint(field_1) + parseint(field_2); }, "enter number of persons (including yourself)"); 

it's implemented other rule. 2 parameters name attributes of 2 other fields want check against. since new rule says field must contain sum of 2 other fields, required , digits rules redundant , can removed.

$("#form2").validate({     errorelement: "span",     rules: {         attendees: {             totalcheck: ['adults', 'children'] // <-- custom rule         },         adults: {             required: true,             digits: true         },         children: {             required: true,             digits: true         }     },     messages: {         adults: "enter number of adults",         children: "enter number of childern"     } }); 

working demo: http://jsfiddle.net/hbxl6/