<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <title>两级连动</title> <script defer> var ar = [[["A"],["A1","A2","A3]],[["B"],["B1","B2","B3"]]];
for (var i=0;i<ar.length;i++) prov.options[prov.options.length]=new Option(ar[i][0],ar[i][0])
function provChanged(i) { city.innerHTML="" for (var j=0;j<ar[i][1].length;j++) city.options[city.options.length]=new Option(ar[i][1][j],ar[i][1][j]) }
provChanged(0);
function show() { alert(prov.value+city.value) } </script> </head> <body>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>两级连动</title> <script defer>
var ar =
[[["A"],["A1","A2","A3]],[["B"],["B1","B2","B3"]]];
for (var i=0;i<ar.length;i++)
prov.options[prov.options.length]=new Option(ar[i][0],ar[i][0])
function provChanged(i)
{
city.innerHTML=""
for (var j=0;j<ar[i][1].length;j++)
city.options[city.options.length]=new Option(ar[i][1][j],ar[i][1][j])
}
provChanged(0);
function show()
{
alert(prov.value+city.value)
}
</script>
</head>
<body>
<select id=prov style="width:100" onchange="provChanged(selectedIndex)"></select>
<select id=city style="width:100"> </body>
</html>
应该如何修改呢?