I am new on angular, I want to change color of radio button is it selected and also want to get that value. I tried a lot but getting $scope is undefined. Here is my code HTML
<form action="" ng-controller="howSoonContr">
                  <div class="form-group">
                    <div data-toggle="buttons">
                      <label class="btn btn-default btn-circle btn-lg active"><input type="radio" name="q1" value="0" ng-change="howSoonClick()" ng-model="time.min"><a>5 mins</a></label>
                      <label class="btn btn-default btn-circle btn-lg"><input type="radio" name="q2" value="1" ng-model="time.min"><a>10 mins</a></label>
                      <label class="btn btn-default btn-circle btn-lg"><input type="radio" name="q3" value="2" ng-model="time.min"><a>20 mins</a></label>
                       <label class="btn btn-default btn-circle btn-lg"><input type="radio" name="q4" value="3" ng-model="time.min"><a>30 mins</a></label>
                        <label class="btn btn-default btn-circle btn-lg"><input type="radio" name="q5" value="4" ng-model="time.min"><a>45 mins</a></label>
                    </div>
                  </div>
               </form>
This is my js
.controller("howSoonContr", function($scope) {
    console.log("we are in howSoonContr");
    //console.log($scope.time);
    //if ($scope.time) {
        console.log("here is the hello " + $scope.time);
        $scope.howSoonClick = function(time) {
            console.log("here is the hello " + $scope.time);
        }
})
Please help me.