Menu flutuante no WordPress no estilo do smmart.es

<script type="text/javascript" src="http://code.jquery.com/jquery-1.11.1.min.js"></script>
<div class="clear" id="catcher"></div><!-- aqui esta el limite -->
<div id="sticky" style="background: #000; width:100%; height: 150px;">
</div>
<p style="margin-bottom: 1200px;">Eeste es un ejemplo para <strong>SEOmundo</strong></p>
<p>Opps! ha desaparecido el mensaje</p>

jQuery(document).ready(function() {
	function isScrolledTo(elem) {
		var docViewTop = jQuery(window).scrollTop(); //num of pixels hidden above current screen
		var docViewBottom = docViewTop + jQuery(window).height();


		var elemTop = jQuery(elem).offset().top; //num of pixels above the elem
		var elemBottom = elemTop + jQuery(elem).height();


		return ((elemTop <= docViewTop));
	}


	var catcher = jQuery('#catcher');
	var sticky = jQuery('#sticky');
	
	jQuery(window).scroll(function() {
		if(isScrolledTo(sticky)) {
			sticky.css('position','fixed');
			sticky.css('top','0');
			sticky.css('margin-top','0');
		} 
		var stopHeight = catcher.offset().top + catcher.height();
		if ( stopHeight > sticky.offset().top) {
			sticky.css('position','relative');
			sticky.css('top', 'auto');
			sticky.css('margin-top','30px');
		}
	});
});