function baner_off()
{
   document.getElementById('baner').style.display='none';
}

function strzalki()
{
        var okno_wys = window.screen.availHeight - 150;
        var linia_wys = document.getElementById("ola").offsetHeight;
        ilosc = Math.floor(linia_wys / okno_wys);

        for (c=1; c<=ilosc; c++)
        {
            var tp=okno_wys*c;
            strzalki_div.innerHTML+="<div style='position: relative;'><div style='position: absolute; left: 440px; top:"+tp+"px;'><a href='#'><img src='img/strzalka_top.gif' style='border: none;'></a></div></div>";
        }
}