function createCookie(name,value,days) {
    if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
    }
    else var expires = "";
    document.cookie = name+"="+value+expires+"; path=/";
    }

    function change_size(punkt) {
    document.getElementById('tresc').style.fontSize=punkt;
    createCookie("textSize", punkt, 90);
    }