/* prvek() vraci prvek objektoveho modelu stranky i ve starem IE */
function prvek(jmeno) {
  var obj=0;
  
  // getElementByID - ne-IE prohlizece a nove verze IE
  if(document.getElementById){
    obj = document.getElementById(jmeno);
  }
  // document.all - stare verze IE
  else if (document.all){
    obj = document.all[jmeno];
  }
  return obj;
}

/* prepne viditelnost prvku */
function prepni(id){
  var el = prvek(id);
  if(el.style){
    (el.style.display == "none") ? el.style.display = "block" : el.style.display = "none";
  }
}

/* SKRIPTY SPECIELNE PRO KOMENTARE: */

/* pocitani napsanych znaku */
function counterchar(){
  var text = prvek("text");
  var span = prvek("charcount");
  span.innerText = text.value.length;
}


function oknoStred(adresa,vyskaOkna,sirkaOkna,nazev){
  x = (screen.width / 2) - (sirkaOkna/2) - 4 ;
  y = (screen.height / 2) - (vyskaOkna/2) - 29 ;
  retezec = "left=" + x + ", top=" +y+ ", width=" + sirkaOkna + ", height=" + vyskaOkna;
  okno = window.open(adresa,nazev,retezec,scrolling="yes");

}

function oknoSex(adresa,vyskaOkna,sirkaOkna,nazev){
  x = (screen.width) - 50 - (sirkaOkna) ;
  y = (screen.height / 2) - 50 - (vyskaOkna / 2) ;
  retezec = "left=" + x + ", top=" +y+ ", width=" + sirkaOkna + ", height=" + vyskaOkna;
  okno = window.open(adresa,nazev,retezec,scrolling="yes");

}

function oknoNkm(adresa,vyskaOkna,sirkaOkna,nazev){
  x = (screen.width) - 30 - (sirkaOkna) ;
  y = (screen.height / 2) - 50 - (vyskaOkna / 2) ;
  retezec = "left=" + x + ", top=" +y+ ", width=" + sirkaOkna + ", height=" + vyskaOkna;
  okno = window.open(adresa,nazev,retezec,scrolling="yes");

}

function runPlayer() {
  window.open('http://www.abradio.cz/player.php?kod=24&quality=asx32','ABradio','width=395,height=250,toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no,copyhistory=no');
}