title: TypeError: Cannot read property 'indexOf' of undefined
body: <p>Node is giving this error while checking the occurrence of a substring:</p>
  <blockquote>
  <p>TypeError: Cannot read property 'indexOf' of undefined'</p>
  </blockquote>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="false" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>var withdraw = project.withdrawal;
                  var uemail = user.eamil;
                  var ans = withdraw.indexOf(uemail) &gt; -1;</code></pre>
  </div>
  </div>
  </p>