// JavaScript Document
function zobrazSkryj(idecko){
el=document.getElementById(idecko).style;
el.display=(el.display == 'block')?'none':'block';
}

function registrace(stav)
{
    var registrovany = document.getElementById("registrovany");
    var neregistrovany = document.getElementById("neregistrovany");

    if (stav) {
        registrovany.style.display = "block";
        neregistrovany.style.display = "none";
    }
    else {
        registrovany.style.display = "none";
        neregistrovany.style.display = "block";
    }
}


  var show_time=false;
  var timerID=null;

  function stop(){
     if (show_time){
         clearTimeout(timerID);
         document.clock.date_time.value=" ";
     }
     show_time=false;
  }

  function start(form){
     var today=new Date();
     var display_value ="Čas: " + today.getHours()
     if(today.getMinutes() < 10){ 
        display_value+=":0" + today.getMinutes();
     }
     else{
        display_value+=":" + today.getMinutes();
     }
     if (today.getSeconds() < 10){
        display_value+=":0" + today.getSeconds();
     }
     else{
        display_value+=":" + today.getSeconds();
     }
     if(today.getHours()>=12){
        display_value+="" 
        /* Here we have a variable called mygreeting where 
           you can store somthing like this:   
           mygreeting ="Good Morning!"; */
     }
     else{
        display_value+=""
        /* Now set mygreeting to: 
           mygreeting ="Good Afternoon!"; */
     } 
     display_value += " - " + today.getDate() + "."  +
        (today.getMonth()+1) + "." + today.getFullYear();
        document.clock.date_time.value=display_value;
        timerID=setTimeout("start()",100);
        show_time=true;
        /* Here have an alert() method do the following: 
           alert(mygreeting); */
  }