title: Get "set" width of a given element
body: <p>I have a div that needs to be given a width. i.e. A width must be manually set, either via CSS or via an inline style (Google Maps requires a set width and I'm trying to implement a fail safe, so to speak. If a developer messes up and fails to specify the width, I'd like to set a default width).</p>
  
  <p>In my JS, I am checking like so:</p>
  
  <pre><code>var width = document.getElementById(this.divId).clientWidth;
  </code></pre>
  
  <p>Unfortunately, this is giving me back <code>1920px</code>, even though a width has not been set (I understand why this is happening).</p>
  
  <p>Is there a way to check if the width has been manually specified or not?</p>
  
  <p>PS: I would like to do this without the aid of libraries such as JQuery.</p>