这是某种实现方式
?
<html>
<head>
<title></title>
<meta name="GENERATOR" content="Microsoft Visual Studio.NET 7.0">
<style type="text/css" id="a">
.hello {
background-color: pink;
}
</style>
<style type="text/css">
.world {
color: #33FF99
}
</style>
<script language="javascript">
var turnback=false;
function setCSS()
{
var ttt = document.getElementById("ttt");
if(turnback){
a.styleSheet.cssText=".hello{background-color:pink;width:"+ttt.value+"px;height:"+ttt.value+"px}";
}else{
a.styleSheet.cssText=".hello{background-color:gray;width:"+ttt.value+"px;height:"+ttt.value+"px}";
} turnback=!turnback;
}
</script>
</head>
<body>
<input type="text" id="ttt">
<button onclick="setCSS()" type="button">
切换背景颜色
</button>
<div class="hello world">
hello world
</div>
<div class="hello world">
hello world
</div>
<div class="hello world">
hello world
</div>
<div class="hello world">
hello world
</div>
</body>
</html>
?