<HTML>
<HEAD>
<script language=JavaScript>
function toNext(obj,str){
if(obj.value.length==str&&obj.nextSibling.nextSibling.type=="text"){
obj.nextSibling.nextSibling.focus()
}
}
function toPrevious(obj,str){
var e = e||event;
var cuurKey = e.keyCode||e.which||e.charCode;
if((cuurKey==8||cuurKey==46)&&obj.value.length==0&&obj.previousSibling.previousSibling.type=="text"){
obj.previousSibling.previousSibling.focus();
obj.previousSibling.previousSibling.value=obj.previousSibling.previousSibling.value;
}
}
</script>
<body>
<input name="yes1" type="text" size="3" maxlength="3" style="" οnkeyup="toNext(this,3)">
<input name="yes2" type="text" size="4" maxlength="4" οnkeyup="toNext(this,4);toPrevious(this,4)">
<input name="yes3" type="text" size="4" maxlength="4" οnkeyup="toPrevious(this,4)">
</body>
</html> 當第一個框輸滿了自動跳到第二個框