title: Setting CSS Expression using $.css() in JQuery
body: <p>I'm trying to set a css expression for an attribute for an element as follows.</p>
  
  <pre><code>var scrollTopExpr = '$(document).scrollTop()';
  var expr = "expression(eval(" + scrollTopExpr + "))";
  $(this).css("top", expr);
  </code></pre>
  
  <p>But i'm getting "Invalid Argument" as an error. Any ideas?</p>