title: Which values should be put in quotation marks and which not in jQuery's animation
body: <p>I was wondering in which cases one should put the values of an animation in quotation marks.</p>
  
  <p><a href="http://api.jquery.com/animate/" rel="nofollow">jQuery</a>'s site doesn't really explains when. I figured it would be when you are giving a unit value: for instance <code>"52px"</code> or <code>"1em"</code> whereas opacity is unit-less (<code>0.9</code>) I don't know what to do with things such as <code>borderStyle</code>, <code>backgroundColor</code>, <code>boxShadow</code>, <code>backgroundImage</code> though and I can't seem to find any examples. Any help and guidelines would be appreciated!</p>