$.addMethod('customFun',function(value, element, param){
     console.log('This is test');
if(confirm('test')){
returntrue;
}
returnfalse
},'custom error message');

$.addMethod('customFun',function(value, element, param){
var customMsg ='';
var result    =true;
if(value.length 
 
<5){
          customMsg ='長度太短';
          result    =false;
}elseif(value.length >20){
          customMsg ='長度太長';
          result    =false;
}
     $.validator.messages.customFun = customMsg;
return result;
});