$(function(){

  function DoOnLoad() {
    CentreVertical();
  }

  function CentreVertical() {
    var hWindow = $(window).height();
    var hWrapper = $("#wrapper").height();
    if(hWrapper + 10 < hWindow) {
      var newMarginTop = (hWindow - hWrapper)/2 + "px";
      $("#wrapper").css("margin-top",newMarginTop);
    } else {
      $("#wrapper").css("margin-top","10px");
    }
  }

  DoOnLoad();

  var resizeTimer = null;
  $(window).bind('resize', function() {
      if (resizeTimer) clearTimeout(resizeTimer);
      resizeTimer = setTimeout(DoOnLoad, 50);
  });

});