function hover_old(X) {document.getElementById(X).src = document.getElementById(X).src.replace(X,X+'_over');}
function normal_old(X) {document.getElementById(X).src = document.getElementById(X).src.replace(X+'_over',X);}
function hover(X) {document.getElementById(X).className="menu_poziome_hover";}
function normal(X) {document.getElementById(X).className="menu_poziome";}
function unhide(X) {
document.getElementById("td_di").className="td_hidden";
document.getElementById("td_op").className="td_hidden";
document.getElementById("td_pp").className="td_hidden";
document.getElementById("td_"+X).className="td_shown";}