title: Backspace key issue in firefox
body: <p>I have an text box and applied Allow Alphabets With Space only using jquery. Its working in chrome But in firefox the backspace key is not working.</p>
  
  <pre><code>&lt;input type="text" placeholder="" id="id1"&gt;
  
  $(function(){
  $('#id1').keypress(function (event) {
        if ((event.which &gt;= 65 &amp;&amp; event.which &lt; 91) || (event.which &gt; 96 &amp;&amp; event.which &lt; 123) || event.which === 32 || event.which===0) {
            return true;
        }
          else {
            event.preventDefault();
        }
   })});
  </code></pre>
  
  <p>Here it is <a href="http://plnkr.co/edit/B1zBQlAoklq1gPlTeokw?p=preview">Plnkr</a></p>