<!-- 把如下代碼加入<body>區域中 -->
<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
var OptLstTxt = new Array;
var OptLstVal = new Array;
var OptLen = 0;
function NoDupl(SelObjFrom, SelObjTo) {
var OldToVal = SelObjTo.options[SelObjTo.selectedIndex].value;
if (OptLen == 0) {
OptLen = SelObjFrom.length;
for (var i = 1; i < OptLen; i++) {
OptLstTxt[i] = SelObjFrom.options[i].text;
OptLstVal[i] = SelObjFrom.options[i].value;
}
}
var j = 1;
for (var i = 1; i < OptLen; i++) {
if (OptLstVal[i] != SelObjFrom.options[SelObjFrom.selectedIndex].value) {
if (j == SelObjTo.length) {
SelObjTo.options[j] = new Option(OptLstTxt[i]);
}
else {
SelObjTo.options[j].text = OptLstTxt[i];
}
SelObjTo.options[j].value = OptLstVal[i];
if (OptLstVal[i] == OldToVal) {
SelObjTo.selectedIndex = j;
}
j++;
}
}
if (SelObjTo.length > j)
SelObjTo.options[(SelObjTo.length - 1)] = null;
}
// End -->
</script>
<form method="POST" name="MForm">
你能在兩邊選取相同的顏色代碼嗎？
<br>
<select name="Color_1" onChange="NoDupl(this,document.MForm.Color_2)">
<option selected value=''>請選擇第一種顏色代碼</option>
<option value='R'>Red</option>
<option value='J'>Yellow</option>
<option value='G'>Green</option>
<option value='B'>Blue</option>
</select>
<select name="Color_2" onChange="NoDupl(this,document.MForm.Color_1)">
<option selected value=''>請選擇另一種顏色代碼</option>
<option value='R'>Red</option>
<option value='J'>Yellow</option>
<option value='G'>Green</option>
<option value='B'>Blue</option>
</select>
</form>