I am currently working on a quiz app.
Simple multi-choise quiz, it's working fine, questions appears, countdown starts.. finally the score is displayed.
Now I wanted to add some "boosters" for the player to enhance the game play so I started with "time booster" that have to allow adding extra time to the player, here is the counter class:

```
<script type="application/javascript">
var myCountdownTest = new Countdown({
  time: 60, 
  width:200, 
  height:80, 
  rangeHi:"minute"
 });
 </script>

```

So I've added a button called "Add time!"

```
<button id='<?php echo $i;?>' class='time btn btn-success' type='button' >Add time!</button>

```

Let's say I want that once the button is clicked, the time counter gets +20 sec so I wrote:

```
$(document).on('click','.time',function() {
  myCountdownTest.time=myCountdownTest.time+20;  
});

```

But that didn't work, what I am missing here?
PS: I want that this button be clickable just one time so the player can use this booster once then the button is locked.