$(document).ready(function(){

     $('html').click(function(e){
      mouseX=e.pageX;
      mouseY=e.pageY;
      var bodyTop = document.documentElement.scrollTop + document.body.scrollTop;
      ..
      //window.outerWidth is not working in IE
      var windowWidth  = $(window).outerWidth();
      var windowHeight = $(window).outerHeight();
      ..
      if(mouseY-bodyTop+popupHeight > windowHeight)
        ...
        ...
      //set the position first. remove the position attr in css   
      $('div').css({position:"absolute",top:popupTop,left:popupLeft});
      $('div').show();
     });
 });