[原]界面上有几个球队名字的列表，将鼠标放到球队名字上就变为红色背景，其他球队背景颜色为白色，点击一个球队的时候就将点击的球队变为fontSize=30字体(fontSize=‘’回到默认)。

window.onload = function () {
            var uls = document.getElementById('ui').getElementsByTagName('li');
            for (var i = 0; i < uls.length; i++) {
                uls[i].onmouseover = function () {
                    this.style.backgroundColor = 'red';
                };
                uls[i].onclick = function () {
                    this.style.fontSize = '30px';
                };
                uls[i].onmouseout = function () {
                    this.style.backgroundColor = '';
                    this.style.fontSize = '12px';
                };
            };
        };
<ul id="ui" style=" list-style-type:none; float:left; margin:0px;">
        <li>湖人</li>
        <li>马刺</li>
        <li>雷霆</li>
        <li>公牛</li>
        <li>火箭</li>
        <li>热火</li>
    </ul>