title: parseInt does not work as expected
body: <p>The answer may be obvious but I don't see</p>
  
  <p>I have a JavaScript object virtualTable. I write :</p>
  
  <pre><code>parseInt(virtualTable["resource_" + resourceId])
  </code></pre>
  
  <p>it returns <code>NaN</code></p>
  
  <p>I check <code>virtualTable["resource_" + resourceId]</code> with an alert and the answer is "690"</p>
  
  <p>If I alert <code>parseInt("690")</code> it works fine and returns 690</p>
  
  <p>What is wrong then?</p>
  
  <p>the whole code :</p>
  
  <pre><code>if(!virtualTable.hasOwnProperty("resource_" + resourceId)) {
      virtualTable["resource_" + resourceId] = "\"" + minutesToFill + "\"";
  }
  
  var timeForTarget = (target.end.getTime() - target.start.getTime()) / 60000;
  var timeInVirtualTable;
  var tooltipInTarget
  
  if(virtualTable["resource_" + resourceId].indexOf("_") == -1) {
      timeInVirtualTable = parseInt(virtualTable["resource_" + resourceId]);
      tooltipInTarget = "";
  } else {
      timeInVirtualTable = parseInt(virtualTable["resource_" + resourceId].substring(0, virtualTable["resource_" + resourceId].indexOf("_")));
      tooltipInTarget = virtualTable["resource_" + resourceId].substring(virtualTable["resource_" + resourceId].indexOf("_"));
  }
  </code></pre>