title: Link tag and media attribute
body: <p>I'm going through a training video on responsive design (lynda dot com). The instructor showed how to link an html doc to 2 different external css files that have screen size-specific formatting. In one example, he wrote the syntax for the medium size screen as follows:</p>
  
  <pre><code>&lt;link rel="stylesheet" type="text/css" media="only screen and (min-width:501px) and (max-width:800px)" href="css/screen_layout_medium.css" /&gt;
  </code></pre>
  
  <p>The media attribute property is in double quotes. However, when i did this in Dw CS6, the html file wouldn't link to it. I then changed it to single quotes and it worked, but I don't know why. Can anyone explain this? </p>