title: How to validate a multiselect Dropdown?
body: <p>So the situation is this: I'm creating a dropdown box using the jquery.multiselect plugin on a form, but I need to check if there's some value selected, if there isn't one or more values selected I wanna throw a alert or something when some one tries to submit the form.</p>
  
  <p><b>The HTML Code</b></p>
  
  <pre><code>&lt;form id="RNA" name="RNA"&gt;
  &lt;select size="5" name="sampleMut[]" multiple="multiple" id="sampleMut"&gt;
  
   &lt;option value="41" &gt;41&lt;/option&gt;
    &lt;option value="48" &gt;48&lt;/option&gt;
    &lt;option value="65" &gt;65&lt;/option&gt;
    &lt;option value="102" &gt;102&lt;/option&gt;
  
  &lt;/select&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p><b>The JavaScript Code</b></p>
  
  <pre><code>$(function(){
   $("#sampleMut").multiselect(); 
  });
  </code></pre>
  
  <p>jQuery version <b>1.8.3</b></p>
  
  <p>jquery.multiselect <b>1.13</b></p>