求大神！！！为啥点俩按钮没反应？
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>display</title>
<script type="test/javatest">
function yincang()
{
var mychar=document.getElementById("con");
mychar.style.display="none";
}
function xianshi()
{
var mycha=document.getElementById("con");
mycha.style.display="block";
}
</script>
</head>
<body>
<h1>欢迎</h1>
<p id="con">这段话可以隐藏也可以不隐藏，厉害吧？哈哈哈哈哈哈哈哈哈哈</p>
<form>
<input type="button" onclick="yincang()" value="隐藏内容"/>
<input type="button" onclick="xianshi()" value="显示内容"/>
</form>
</body>
</html>
