<!DOCTYPE html>
<html>
<head>
<title>134</title>
<meta charset="utf-8">
<script type="text/javascript">
function ac()
{
var a=[];
var b,i;
var s=[];
a=document.getElementById("a");
b=document.getElementById("b");
if (a.selectedIndex==0)
{
b.innerHTML=' <option value="">汕头</option>\
<option value="">广州</option>\
<option value="">深圳</option>';
}
else if (a.selectedIndex==1)
{
b.innerHTML=' <option value="">北海</option>\
<option value="">玉林</option>\
<option value="">桂林</option>';
}
else if (a.selectedIndex==2)
{
b.innerHTML=' <option value="">福州</option>\
<option value="">厦门</option>\
<option value="">莆田</option>';
}
}
</script>
</head>
<body>
<label>省</label>
<select id="a" onchange="ac()">
<option value="">广东</option>
<option value="">广西</option>
<option value="">福建</option>
</select>
<label>市</label>
<select id="b">
<option value="">汕头</option>
<option value="">广州</option>
<option value="">深圳</option>
</select>
</body>
</html>