title: jQuery plugin for formatting inputs
body: <p>I want to accept values in any of the following format:</p>
  
  <ul>
  <li>-$5</li>
  <li>-$5.00 </li>
  <li>$5 </li>
  <li>$5.00</li>
  </ul>
  
  <p>Is it possible to do that using <a href="http://digitalbush.com/projects/masked-input-plugin/" rel="noreferrer">Masked Input Plugin</a>?</p>
  
  <p>If not, what plug-in am I looking for?</p>
  
  <p>How do I indicate a character is optional?</p>
  
  <p>The code I've got so far</p>
  
  <pre><code>$.mask.definitions['~']='[ +-]';
  $(".currency").mask("~$9");
  </code></pre>