Detekcia smeru vstupu kurzora na element

var captureElement = document.getElementById("capture-element");

function getSide(e){
  var e = e || window.event;
  var target_width = e.target.offsetWidth,
      target_height = e.target.offsetHeight,
      coord_x = e.offsetX,
      coord_y = e.offsetY;
  
  var sidesOffset = [coord_y,target_width-coord_x,target_height-coord_y,coord_x];
  var names = ["top","right","bottom","left"];
  
  var minOffset = Math.min.apply(null,sidesOffset);
  
  return names[sidesOffset.indexOf(minOffset)];
};

captureElement.onmouseover = function(e){
  getSide(e); //nahoře,vpravo,dole,vlevo 
};
captureElement.onmouseout = function(e){
  getSide(e); //nahoře,vpravo,dole,vlevo 
};

if (target.nodeType == 3) // defeat Safari bug
    {
    target = target.parentNode;
    }

if(typeof event.offsetX === "undefined" || typeof event.offsetY === "undefined") {
   var targetOffset = $(event.target).offset();
   event.offsetX = event.pageX - targetOffset.left;
   event.offsetY = event.pageY - targetOffset.top;
}

captureElement.onmouseover = function(event){
alert(event) // a mel by tam byt event ff nebo window.event a neni treba delat podminkovani
  getSide(e); //nahoře,vpravo,dole,vlevo 
};

captureElement.onmouseover = function(event){
alert(event) // a mel by tam byt event ff nebo window.event a neni treba delat podminkovani
  getSide(e); //nahoře,vpravo,dole,vlevo 
};

if (targ.nodeType == 3) { // defeat Safari bug
  targ = targ.parentNode;
}