var x = 0;
var y = 0;

function hooverOn(text) {
if (window.Event) {
document.captureEvents(Event.MOUSEMOVE);
}
document.onmousemove = getXY;

/* jine hodnoty pro IE a FF */
var jmenoProhlizece=navigator.appName; 

  // pozice boxu  
  if (jmenoProhlizece=="Microsoft Internet Explorer" && navigator.appVersion>6) {
    y=document.body.scrollTop+y;
    poztop=document.body.scrollTop;
  }
  
  else {
    
      if (jmenoProhlizece=="Microsoft Internet Explorer") {
      y=document.documentElement.scrollTop+y;
       poztop=document.documentElement.scrollTop;
      }
      else {
       poztop=window.pageYOffset;
      }
      
  }
  
  //vyska zobrazene casti
  if (jmenoProhlizece=="Netscape") {
   spodek = poztop + window.innerHeight;
   leva = window.innerWidth;
  }
  else {
   spodek = poztop + document.body.clientHeight;
   leva = document.body.clientWidth;
  }

  vhel = get_current_height(document.getElementById("hoover"));

// osetreni proti preteceni pod okno
if (spodek<(y+vhel+35)) {
 y=y-vhel-25;
}

if (leva<(x+160)) {
    if (jmenoProhlizece!="Microsoft Internet Explorer") {
    x=x-340;
    }
    else {
    x=x-330;
    } 
}

document.getElementById("hoover").style.top=y+15+"px";
document.getElementById("hoover").style.left=x+15+"px";
document.getElementById("hoover").style.display="";
document.getElementById("hoover").innerHTML=text;
}

function getXY(e) {
x = (window.Event) ? e.pageX : event.clientX;
y = (window.Event) ? e.pageY : event.clientY;
}

function hooverOff() {
document.getElementById("hoover").style.top="-1000px";
document.getElementById("hoover").style.left="-1000px";
document.getElementById("hoover").style.display="none";
}

function get_current_height($element)
  {
  var ee;
  try
    {
    var $cs=document.defaultView.getComputedStyle($element,'');
    $val=style2px($cs.getPropertyValue("height"));
    }
  catch(ee)
    {
    $val=($element.offsetHeight);
    if($val<0)$val=0;
    }
  return $val;
  }