怎么让下拉列表的值改变时，然后下面的文本域隐藏或显是
function setHide(){
document.getElementById('divEnglish').style.visibility="hidden";
document.getElementById('divChinese').style.visibility="hidden";
}
function setShow()
{
document.getElementByTag('div').style.visibility="visible";
}
function articleChange()
{
var text=document.getElementByName('article').value;
//onchange="javascript:return change(this.options[this.selectedIndex].value
if(text=="English"&&document.getElementByName("divEnglish")=="divEnglish")
{
setShow();
}
if(text=="Chinese")
{
}
}
</script>
</head>
<body onLoad="startTime(),setHide()">
<div><span>时间：</span>秒<span></span></div>
<hr />
<form id="articleList" name="articleList" onchange="articleChange()">
<select name="article">
<option value="null">[请选择]</option>
<option value="English" >English</option>
<option value="Chinese">Chinese</option>
</select>
<input type="submit" value="提交" />
<textarea cols="10" rows="10" id="divEnglish">
fsdfsdfsdfsdfsdf
</textarea>
<textarea cols="10" rows="10" id="divChinese">
中文
</textarea>
</form>
<input type="text" id="keyTest" onClick="" onKeyDown="test()" onKeyPress=""/>
