 the ability to stop the execution of an action before it starts.</p>
   <pre class="prettyprint linenums">
   $('#myModal').on('show', function (e) {
       if (!data) return e.preventDefault() // stops modal from being shown
   })
   </pre>
</div>



<!-- Transitions
================================================== -->
<div class="bs-docs-section">
   <div class="page-header">
      <h1 id="js-transitions">Transitions <small>bootstrap-transition.js</small></h1>
   </div>
   <h3>About transitions</h3>
  