document.getElementById('link').onmouseover = show;
document.getElementById('link').onmouseout = hide;
function show() {
    document.getElementById('ul1').style.display = 'block';
    document.getElementById('link').style.background ='red';
};
function hide() {
    document.getElementById('ul1').style.display = 'none';
    document.getElementById('link').style.background = ' #f1f1f1';