$(document).ready(function() {

 var $parent,
     windowWidth,
     windowHeight;

  //get actual window size
  function winSize() {
     windowWidth = $(window).width(),
     windowHeight = $(window).height();
  }
  winSize();
  $(window).resize(winSize);
 //tooltip fadeIn and fadeOut on hover
 $('.tooltip').each(function() {

    $(this).parent().hover(function() {
      $(this).find('.tooltip').fadeIn('fast');
    }, function() {
       $(this).find('.tooltip').fadeOut('fast');
    });

 });


//tooltip position
  $(document).mousemove(function(e) {
    var mouseY = e.clientY,
        mouseX = e.clientX,
        tooltipHeight,
        tooltipWidth;

    $('.tooltip').each(function() {
      var $tooltip = $(this);
      tooltipHeight = $tooltip.outerHeight();
      tooltipWidth = $tooltip.width();
      $parent = $tooltip.parent();

      $tooltip.css({
        'left':mouseX,
        'top':mouseY+20
       });

      //reposition
      if (tooltipWidth + mouseX+ 20> windowWidth) {
       $tooltip.css({
        'left':mouseX-tooltipWidth-20
       });
      }

      if (tooltipHeight + mouseY +20 > windowHeight) {
        $tooltip.css({
        'top':mouseY-20-tooltipHeight
       });
      }
    });//end each
 });//tooltip position


});//end ready