title: Recommended way to find typos in JavaScript
body: <p>I have developed a JavaScript file which I use in the context of a WordPress plugin. The jQuery contains a typo:</p>
  
  <pre><code>alert('prv_requestSelectionComplement check odds_pos for horse_id='+tmpSel.horse_id+' oddsPositionLimit='.JSON.stringify(oddsPositionLimit)+' odds_pos='+complement.odds_pos);                              
  </code></pre>
  
  <p>You see: Before <code>JSON</code> I used the PHP '.' instead of the JavaScript '+'.</p>
  
  <p>I did not get any error nor warning. The function just stopped working. It took me a while to spot the problem with careful code review. Is there a possibility to get a reasonable error message without double checking all the places where I edited? For example using Firebug?</p>
  
  <p>What is the recommended way to deal with this problem?</p>