<script type="text/javascript">
if (y.length==x.maxLength)
if (next<document.getElementById("myForm").length)
document.getElementById("myForm").elements[next].focus()
<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 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)">