title: javascript: define a variable if it doesn't exist
body: <p>i feel like im trying to do something super simple, but just being stupid about it.</p>
  
  <p>all i want to do is see if a variable has been set previously, and if it has NOT, set it with a default value....here is a sample:</p>
  
  <pre><code>if(!embed_BackgroundColor) {
      var embed_BackgroundColor;
      embed_BackgroundColor = "#F4F4F4";
  }
  </code></pre>
  
  <p>so, once you stop laughing at my code....WHY is it overwriting the variable no matter what?</p>
  
  <p>please save my nerves;)</p>