单击问好
<script language=javascript>
function hello() //3.问好函数
{
alert("您好！");
}
</script>
</head>
<body>
<p align="center"><font size="5" color="#0000FF"><b>单击问好</b></font></p>
<form name="form1"> //1.表单1
<p align="center">
<input type="button" value="单击问好按钮" name="hello_button">
//2.单击问好按钮
</form>
<script language=javascript>
document.form1.hello_button.onclick=hello;
//1.表单1，2.单击问好按钮，3.单击事件处理：问好函数
</script>