$(function() {  
  $('#menu ul li').hover(function() {
    if ($(this).children('ul').length) {
      $(this).children('ul').show();
    }
  }, function() {
    if ($(this).children('ul').length) {
      $(this).children('ul').hide();
    }	    
  });
});

$(window).load(function() {
  centerize = function() {
    contentHeight = $('#wrapper').height();
    documentHeight = $(document).height();
        console.log(contentHeight);
            console.log(documentHeight);
    if (documentHeight != contentHeight) {
      center = Math.ceil(((documentHeight - contentHeight) / 2));
      $('#wrapper').css({'marginTop': center+'px'});
    }
  }

  centerize();
});