function Foto(url,w,h) {
  if(screen.width>w) wwidth = w; else wwidth = screen.width;
  if(screen.height>h) wheight = h; else wheight = screen.height;
  wtop = screen.height/2-wheight/2;
  wleft = screen.width/2-wwidth/2;
  window.open('/foto-detail.html?f='+url+'&w='+w+'&h='+h,'fotodetail','width='+wwidth+',height='+wheight+',top='+wtop+',left='+wleft+',status=yes,resizable=yes');
}

function objKontrola() {
  if(document.objform.jmeno.value == '') {
    alert('Nevyplnili jste jméno a příjmení. Name and Surname missing. Name und Vorname.');
    document.objform.jmeno.focus();
    return false;
  }
  if(document.objform.adresa.value == '') {
    alert('Nevyplnili jste adresu. Address missing. Adresse.');
    document.objform.adresa.focus();
    return false;
  }
  if(document.objform.telefon.value == '') {
    alert('Nevyplnili jste telefon. Telephone missing.');
    document.objform.telefon.focus();
    return false;
  }
  if(document.objform.email.value == '') {
    alert('Nevyplnili jste email. Email missing.');
    document.objform.email.focus();
    return false;
  }
}
function fSnidani() {
  if(document.objform.pristylka.checked==true) {
    document.objform.snidani.value = document.objform.osob.value*1 + 1;
  } else {
    document.objform.snidani.value = document.objform.osob.value;
  }
}