title: Reset validation and clear validation message for Asp.Net MVC custom validation
body: <p>I'm using MVC 3 with jQuery 1.7.2 and I've implemented some custom validation on client and server side to validate that a certain textarea has text if a checkbox is checked. </p>
  
  <p>My client side code to implement unobstrusive validation looks like this:</p>
  
  <pre><code> $.validator.addMethod("requiredif", function (value, element, params) {
      if (value) {
        var id = '#' + params["otherproperty"];
        var control = $(id);
        if (control.val() == '') {
          return false;
        }
      }
  
      return $.validator.methods.required.call(this, value, element, params);
  });
  
  $.validator.unobtrusive.adapters.add("requiredif", ["otherproperty"], function(options) {
     options.rules["requiredif"] = options.params;
     options.messages["requiredif"] = options.message;
  });
  </code></pre>
  
  <p>My problem is that even though the validation fires if I subsequently go back and untick the checkbox (i.e. text is no longer required), the validation message stays put and validation is not cleared.</p>
  
  <p>I have tried the following to clear the validation:</p>
  
  <pre><code> $('#Dashboard').on('change', '#Damaged', null, function () {
     var validator = $('#Gridform').validate();
     validator.resetForm();
   });
  </code></pre>
  
  <p>But this doesn't make any difference.</p>
  
  <p>What I would like is for the validation to work the same as the standard validation does i.e. when I untick the checkbox or enter content into the textarea the validation is cleared/reset.</p>