function menu_over(el) {
    el.style.background = "url(grafika/left_menu_active.png)";     
}

function menu_out(el) {
    el.style.background = "url(grafika/left_menu.png)";     
}


function open_menu() {
    el = document.getElementById("dynamic_menu");
    el.style.visibility = "visible";
}

function hide_menu() {
    el = document.getElementById("dynamic_menu");
    el.style.visibility = "hidden";
}

function show_img(name) {
    var div = document.getElementById('main_img_div');
    var img = document.getElementById('main_img');
    var header = document.getElementById("header");
    var height = document.documentElement.clientHeight;
    var top = height / 2;

    img.src = 'img.php?a=' + name + '&typ=full';
    div.style.top = top + 100 + "px";
    div.style.display = "block";
}

function hide_img() {
    var div = document.getElementById('main_img_div');
    var img = document.getElementById('main_img');
    
    img.src = "grafika/blank.jpg";
    div.style.display = "none";
}