JavaScript学习例子

<input type="password" onblur="checkPassword(this)">

<script >
    function checkPassword(object) {
        if (object.value.length <= 4) {
            alert("密码长度过短");
            object.focus();
            object.select();
        }
    }
</script>

<script >
    if (confirm("你想退出吗")) {
        window.location.href = "http://www.baidu.com";
    } else {
        alert("hi");
    }
</script>
<script >
    with(document) {
        write("屏幕设定值<br>");
        write("实际高度：",screen.availHeight,"<br>");
        write("实际宽度：",screen.availWidth,"<br>");
        write("屏幕区域高度：",screen.height,"<br>");
        write("屏幕区域宽度：",screen.width,"<br>");
    }
</script>
<script >

    // event参数是系统生成并传递过来的
    function getEvent(event) {
        alert("事件类型：" + event.type);
    }
    document.write("单击...");

    document.onmousedown = getEvent;

</script>
<input type="button" value="click" id="button1">

<script >
    var v = document.getElementById("button1");
    v.onclick = clickHandler;
    function clickHandler(event) {
        alert(event.type);
    }
</script>
<input type="button" value="click" id="button1">

<script >
    var v = document.getElementById("button1");
    v.onclick = clickHandler;
    function clickHandler() {
        alert("I am a button!");
    }
</script>