input 点击背景改变颜色
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<script type="text/javascript">
function myfovus(x) {
x.style.background="red"
}
</script>
姓名：<input type="text" onfocus="myfovus(this)"></input>
</body>
</html>