java - How to check errors before form submission via ajax in liferay -

i created form age field name , checking whether number or not.but form submitted showing ajax response , after showing error. don't want form submitted when there error in form field named 'age' .so how prevent that. code follows:-

<%@ taglib uri="http://java.sun.com/portlet_2_0" prefix="portlet" %> <%@ taglib uri="http://liferay.com/tld/theme" prefix="theme" %> <%@ taglib uri="http://liferay.com/tld/aui" prefix="aui" %> <theme:defineobjects/> <portlet:defineobjects /> <portlet:resourceurl var="resourceurl"/> <script type="text/javascript"> function callserveresource(){     aui().use('aui-io-request', function(a){         a.io.request('<%=resourceurl.tostring()%>', {                method: 'post',                form: {                    id: 'fm'                },                on: {                    success: function() {                     alert(this.get('responsedata'));                    }               }             });     }); }  aui().use(         'aui-form-validator',         function(a) {             new a.formvalidator(                 {                     boundingbox: '#fm',                     rules: {                         age:                         {                             number:true                         }                     }                 }             )         }     );  </script> <form name="fm" id="fm"> full name:<input type="text" name="fullname"/> <br/> age:<input type="text" name="age"/> <br/> <input type="button" value="submit form data" onclick="callserveresource()"> </form> 

try this. before a.io.request execute code triggers form validation. in case of validation error, exit function or want. code present in core portlet.js.

    var form = a.one(formselector)      var liferayform = liferay.form.get(form.attr('id'));      if (liferayform) {         var validator = liferayform.formvalidator;          if (a.instanceof(validator, a.formvalidator)) {             validator.validate();              haserrors = validator.haserrors();              if (haserrors) {                 validator.focusinvalidfield();                  return;             }         }     }