title: how to access an object (simpleXML) variable name using a string?
body: <p>i need to access a simplexml object using a string. ie.</p>
  
  <p><code>$x-&gt;a-&gt;b = 'obj';</code>
  <code>$s = 'a-&gt;b';</code>
  <code>echo $x-&gt;$s;</code></p>
  
  <p>but it doesn't seem to work...</p>
  
  <p>please help!</p>
  
  <p>:)</p>