JavaScript动态修改Div属性的实现方法

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Javascript控制div属性变化</title>
<style> 
#outer{width:500px;margin:0 auto;padding:0;text-align:center;}
#div1{width:100px;height:100px;background:black;margin:10px auto;display:block;}
</style>
<script> 
var changeStyle = function (elem, attr, value)
{
 elem.style[attr] = value
};
window.onload = function ()
{
 var oBtn = document.getElementsByTagName("input");
 var oDiv = document.getElementById("div1");
 var oAtt = ["width","height","background","display","display"];
 var oVal = ["200px","200px","red","none","block"];
 for (var i = 0; i < oBtn.length; i++)
 {
  oBtn[i].index = i;
  oBtn[i].onclick = function ()
  {
   this.index == oBtn.length - 1 && (oDiv.style.cssText = "");
   changeStyle(oDiv, oAtt[this.index], oVal[this.index])
  }
 }
};
</script>
</head>
<body>
<div id="outer">
<input type="button" value="变宽" />
<input type="button" value="变高" />
<input type="button" value="改变颜色" />
<input type="button" value="隐藏" />
<input type="button" value="重置" />
<div id="div1"></div>
</div>
</body>
</html>