下拉菜单

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
</HEAD><BODY>
<form method=post name=fm>
<select onchange=chg(selectedIndex) name=a>
<option>亚洲
<option>欧洲
<option>美洲
</select>
<select name=b onchange="r.value=value">
<option>请选择
</select>
<input name=r id=r>
</form>
<script>
var arr=[["中国","日本","朝鲜","新加坡"],["英国","法国","意大利"],["美国","加拿大","巴西"]]
function chg(i){
with(document.fm.b){
length=0;
for(j=0;j<arr[i].length;j++)
options.add(new Option(arr[i][j],arr[i][j]))
document.fm.r.value=value+document.fm.a.value
}
}
chg(0)
</script></BODY>
</HTML>