function createCookie(name, value, days)
{
  if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
    }
  else var expires = "";
  document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name)
{
  var ca = document.cookie.split(';');
  var nameEQ = name + "=";
  for(var i=0; i < ca.length; i++) {
    var c = ca[i];
    while (c.charAt(0)==' ') c = c.substring(1, c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);
    }
  return null;
}

function eraseCookie(name)
{
  createCookie(name, "", -1);
}

function show()
{
  submenu=document.getElementById('menusub').style;
  submenu.display='block';
  createCookie('menusub','block');
}

function hide()
{
  submenu=document.getElementById('menusub').style;
  submenu.display='none';
  eraseCookie('menusub');
}

function displaySub()
{
  submenu=document.getElementById('menusub').style;
  submenu.display=(readCookie('menusub'))?'block':'none';
}

function popup(url,jmeno,w,h){
  posx=(screen.width-w)/2;
  posy=(screen.height-h)/2;
  window.open(url,jmeno,"resizable=yes,menubar=no,status=no,location=no,toolbar=no,scrollbars=no,width="+w+",height="+h+",top="+posy+",left="+posx);
}

function zavri(){
  window.opener.location.reload();
  window.close();
}

function potvrzeni(dotaz, presmerovani)
{
  if(window.confirm(dotaz)) {
    location.href=presmerovani;
  }
}