function hoverLink(node) {
    var name = node.href.substring(node.href.lastIndexOf('/') + 1, node.href.lastIndexOf('.'))
    var img = node.firstChild
    img.src = 'img/' + name + 'ant.png'

    node.onmouseout = function() {
        img.src = 'img/ant.png'
        node.onmouseout = ''
    }
}

function openMenu(node) {
    for (; node.nodeType != 1; node = node.nextSibling) {}
    if (node.style.display)
        node.style.display = ''
    else
        node.style.display = 'block'
}