function popUp(menuName,stav) {
   objekt = document.getElementById(menuName);

   if (stav) {
        objekt.style.visibility = "visible";
   } 
   else {
        objekt.style.visibility = "hidden";
   }
}

function sbalitRozbalit(id)
{
    var el=document.getElementById(id);
    if(el.style.display != 'block')
    {
        el.style.display='block';
    }
    else 
    {
        el.style.display='none';
    }
    return false;
}
function checkMail(alert1, alert2)
{
    if (document.mailform.adress.value == "")
    {
        alert (alert2);
        document.mailform.adress.focus();
        return false;
    }
    else 
    {
        vyraz = new RegExp("^[^@]+@[^.]+\..+$");
        if (!vyraz.test(document.mailform.adress.value))
        {
            alert(alert1);
            document.mailform.adress.focus();
            return false;
        }
    }
    return true;
}

function show_stehovani()
{
	document.getElementById("stehovani").style.display="block";
	document.getElementById("button_close").style.display="block";
}
function hide_stehovani()
{
	document.getElementById("stehovani").style.display="none";
	document.getElementById("button_close").style.display="none";
}