title: Javascript parsing int64
body: <p>How can I convert a long integer (as a string) to a numerical format in Javascript without javascript rounding it?</p>
  
  <pre><code>var ThisInt = '9223372036854775808'
  alert(ThisInt+'\r' +parseFloat(ThisInt).toString()+'\r' +parseInt(ThisInt).toString());
  </code></pre>
  
  <p>I need to perform an addition on it before casting it back as a string &amp; would prefer not to have to slice it two if at all possible.</p>