var fields = ['url', 'email', 'alt', 'objednavatel', 'adresa', 'ico', 'ic_dph', 'or', 'banka', 'zastupenie', 'popis'];

for (var id in fields){ //nastavenie dlzok a udalosti
    var el = document.getElementById(fields[id]+'Limit');
    if (el!=null){
        el.className = "limitSpan";
        var elText = document.getElementById(fields[id]);
        el.innerHTML = (fields[id]=='popis' ? 300 : elText.maxLength) - elText.value.length;
        elText.onkeyup = function() { countChars(this.id); };
        elText.onkeypress = function() { countChars(this.id); };
    }
}

//nastala udalost, prepocitat znaky
function countChars(id){
    var el = document.getElementById(id+'Limit');
    if (el!=null){
        var elText = document.getElementById(id);
        if ((el.innerHTML = (id=='popis' ? 300 : elText.maxLength) - elText.value.length)==0){
            elText.value = elText.value.substring(0, (id=='popis' ? 300 : elText.maxLength));
        }
    }
}

var getKeys = function(obj){
   var keys = [];
   for(var key in obj){
      keys.push(key);
   }
   return keys;
}

function submitPreview(){
    var form = document.getElementById('submitForm');
    form.action = 'preview-logo.php';
    form.target = 'backgroundSubmit';
    form.submit();
    form.action = 'pridat-logo/';
    form.target = '_self';
}