title: add css rule using jquery
body: <p>i got a css rule like this:</p>
  
  <pre><code>#imgwrapper {display: block;position: relative;width:auto;height:auto;}
  </code></pre>
  
  <p>so i got a hyperlink that when it's clicked, it should add a css rule to #imgwrapper like this:</p>
  
  <pre><code>#imgtarget, #imgwrapper img {cursor:crosshair;}
  </code></pre>
  
  <p>how should i do it??</p>
  
  <p>i tried jquery .css() api but it aint working..</p>