怎么能点击按钮才填出文字啊
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>函数调用</title>
<script type="text/javascript">
function contxt() //定义函数
{
alert("哈哈,调用函数了!");
}
contxt();
</script>
</head>
<body>
<form>
<input type="button" value="点击我" onclick=" " />
</form>
</body>
</html>