​x
 
<html>
<head>
<script type="text/javascript">
function checkLen(x,y)
{
if (y.length==x.maxLength)
    {
    var next=x.tabIndex
    if (next<document.getElementById("myForm").length)
        {
        document.getElementById("myForm").elements[next].focus()
        }
    }
}
</script>
</head>
​
<body>
<p>这段脚本在达到文本框的最大长度时跳到下一个文本框：</p>
​
<form id="myForm">
<input size="3" tabindex="1" maxlength="3" onkeyup="checkLen(this,this.value)">
<input size="2" tabindex="2" maxlength="2" onkeyup="checkLen(this,this.value)">
<input size="3" tabindex="3" maxlength="3" onkeyup="checkLen(this,this.value)">
</form>
</body>
​
</html>
​