if (document.images) {
    // Shop
    Pic1on = new Image();
    Pic1on.src = "./images/headerover_05.jpg"; 
    Pic1off = new Image();
    Pic1off.src = "./images/header_05.jpg";
    // Tovary
    Pic2on = new Image();
    Pic2on.src = "./images/headerover_07.jpg"; 
    Pic2off = new Image();
    Pic2off.src = "./images/header_07.jpg";
    // Uslugi
    Pic3on = new Image();
    Pic3on.src = "./images/headerover_09.jpg"; 
    Pic3off = new Image();
    Pic3off.src = "./images/header_09.jpg";
    // Kontakty
    Pic4on = new Image();
    Pic4on.src = "./images/headerover_11.jpg"; 
    Pic4off = new Image();
    Pic4off.src = "./images/header_11.jpg";
}
function picon(imja) {
    if (document.images) {
       document[imja].src = eval(imja + "on.src");
}
}
function picoff(imja) {
    if (document.images) {
       document[imja].src = eval(imja + "off.src");
}
}