(function($) {  
   
 $.fn.centerVertical = function() {
	return this.each(function() {     
		
		var  $this = $(this);
		var windowHeight = jQuery(window).height();
		
		var elementHeight =  $this.outerHeight();
		
		$this.css('marginTop','+'+((windowHeight-elementHeight)/2)+'px');

	});
	
 }  
 })(jQuery);