诶，我来修改一下吧
<script ID="clientEventHandlersJS" LANGUAGE="javascript"><!--
function T1_onkeyup() {
if(document.card.T1.value.length==4){
document.card.T2.focus();
}
}
function T2_onkeyup() {
if(document.card.T2.value.length==4){
document.card.T3.focus();
}
}
function T3_onkeyup() {
if(document.card.T3.value.length==4){
document.card.T4.focus();
}
}
//-->
</script>
在<body>...</body>之间加入如下代码：
<form method="POST" name="card" action>
输入字符：
<input type="text" name="T1" size="4" maxlength="4" LANGUAGE="javascript" onkeypress="return T1_onkeyup()">-
<input type="text" name="T2" size="4" maxlength="4" LANGUAGE="javascript" onkeypress="return T2_onkeyup()">-
<input type="text" name="T3" size="4" maxlength="4" LANGUAGE="javascript" onkeypress="return T3_onkeyup()">-
<input type="text" name="T4" size="4" maxlength="4">
</form>
补充：asp教程,客户端相关打印 
