AngularJS Form Validation

<div ng-form="forminside" ng-repeat =" item in passengerCount"> 
        <div class="form-group"  ng-class="{ 'has-error' : item.token.username.$invalid && !item.token.username.$pristine }">
            <label>Username</label>
            <input type="text" name="username" class="form-control" ng-model="item.token.username" ng-minlength="3" ng-maxlength="8">
            <p ng-show="item.token.username.$error.minlength" class="help-block">Username is too short.</p>
            <p ng-show="item.token.username.$error.maxlength" class="help-block">Username is too long.</p>
        </div>
      </div>
        
        <button type="submit" class="btn btn-primary" ng-disabled="userForm.forminside.$invalid">Submit</button>
        
    </form>
  </div>

</div>
</div>
</div>