求大神帮助，实现option选项切换背景颜色

[a1771449051]

<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title></title>
</head>
<style type="text/css">
body{background-color: blue;}

</style>
<body>
<script type="text/javascript">
function changecolor(){

var color=document.getElementById("sel").value;

this.style.backgroundColor=color
}
</script>
<select id="sel" onchange="changecolor()">
<option value="white">白色</option>
<option value="blue">蓝色</option>
<option value="red">红色</option>
<option value="yellow">黄色</option>
</select>


</body>
</html>

[slwsss]

document.body.style.backgroundColor=color document.getElementById("sel").style.backgroundColor=color

[似梦飞花]

<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title></title>
</head>
<style type="text/css">
    body{background-color: blue;}
</style>
<body>
<script type="text/javascript">
    function changecolor(me){
        document.body.style.backgroundColor=me[me.selectedIndex].value;
    }
</script>
<select id="sel" onchange="changecolor(this)">
    <option value="white">白色</option>
    <option value="blue">蓝色</option>
    <option value="red">红色</option>
    <option value="yellow">黄色</option>
</select>


</body>
</html>