title: slideToggle on multiple items, if one is open close that one before opening the other
body: <p>I have this little bit of JS i done, simple stuff i know but wondering what the best way would to be if i expanded one and click on another to expand any that are open that would close before the other one then opened.</p>
  
  <p>JS</p>
  
  <pre><code>/* Expand course details */
  $('.expandCourse').on('click',function() {
    var courseID = $(this).attr('ID');
    console.log(courseID);
    $("."+courseID).slideToggle();
    return false;
  });
  </code></pre>
  
  <p>HTML Example:</p>
  
  <pre><code>&lt;a href="#" id="link_1" class"expandCourse"&gt;test link 1&lt;/a&gt;
  &lt;div class="link_1" style="display:none;&gt;content here&lt;/div&gt;
  
  &lt;a href="#" id="link_2" class"expandCourse"&gt;test link 2&lt;/a&gt;
  &lt;div class="link_2" style="display:none;&gt;content here&lt;/div&gt;
  
  &lt;a href="#" id="link_3" class"expandCourse"&gt;test link 3&lt;/a&gt;
  &lt;div class="link_3" style="display:none;&gt;content here&lt;/div&gt;
  </code></pre>
  
  <p>Thanks in advance!</p>