function popup(url) {
    newwindow=window.open(url,'name','height=350,width=350,location=no,menubar=no,status=no,resizable=yes');
    if (window.focus) {newwindow.focus()};
    return false;
}

function format_clock(t){
    var ret = "";
    var tmp = 0;
    
    if ( t >= 31536000 ){
        tmp = parseInt(t / 31536000);
        t -= tmp * 31536000;
        ret = ret + ' ' + tmp + 'y';
    }
    
    if ( t >= 86400 ){
        tmp = parseInt(t / 86400);
        t -= tmp * 86400;
        ret = ret + ' ' + tmp + 'd';
    }

    if ( t >= 3600 ){
        tmp = parseInt(t / 3600);
        t -= tmp * 3600;
        ret = ret + ' ' + tmp + 'h';
    }
    
    if ( t >= 60 ){
        tmp = parseInt(t / 60);
        t -= tmp * 60;
        ret = ret + ' ' + tmp + 'm';
    }
    
    if ( t > 0 ){
        ret = ret + ' ' + t + 's';        
    }
    
    return ret;
}

var tostart = -1;
var toend = -1;

function timer(start, end){
    var timer = document.getElementById('timer');
        
    if ( !timer ) return;

    if ( tostart == -1 ) tostart = start;
    if ( toend == -1 ) toend = end;    

    tostart = tostart - 1;
    toend = toend - 1;

    if ( tostart > 0 ){
        if ( tostart < 10 * 60 ) timer.style.color = "red";
        else timer.style.color = "";
        timer.innerHTML = "Natjecanje počinje za " + format_clock(tostart);
    }
    else if ( toend > 0 ){
        if ( toend < 10 * 60 ) timer.style.color = "red";    
        else timer.style.color = "";
        timer.innerHTML = "Preostalo vrijeme: " + format_clock(toend);
    }    
    else {
        timer.style.color = "";
        timer.innerHTML = "Natjecanje završeno";
    }
        
    
}