parentElement and commonParentElement for getting parent element
<p>parentElement( <a href="http://msdn.microsoft.com/en-us/library/ms534327(VS.85).aspx" rel="nofollow">http://msdn.microsoft.com/en-us/library/ms534327(VS.85).aspx</a> ) and commonParentElement( <a href="http://msdn.microsoft.com/en-us/library/aa704196(VS.85).aspx" rel="nofollow">http://msdn.microsoft.com/en-us/library/aa704196(VS.85).aspx</a> ) are two methods in javascript. </p>

<p>When should I use these methods for getting the parent element?</p>
