<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>
又或者用以下方法
<html>
<head>
<script type="text/javascript">
function checkLen(obj,id)
{
if (obj.value.length==obj.maxLength)
{
document.getElementById(id).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>
<input id="5" size="3" tabindex="1" maxlength="3" onkeyup="checkLen(this,'6')">
<input id="6" size="2" tabindex="2" maxlength="2" onkeyup="checkLen(this,'7')">
<input id="7" size="3" tabindex="3" maxlength="3" >
</body>