要创建基于域的Cookie，请在Cookie上设置domain和path属性，例如-
domain=.example.com
您可以尝试运行以下代码以了解如何创建基于域的Cookie-
<html>
<head>
<script>
<!--
function WriteCookie() {
if( document.myform.customer.value == "" ){
alert("输入一些值！");
return;
}
cookievalue= escape(document.myform.customer.value) + ";";
document.cookie = "name=" + cookievalue + ";
domain=.example.com;path=/";
document.write ("Setting Cookies : " + "name=" + cookievalue );
}
//-->
</script>
</head>
<body>
<form name = "myform" action = "">
Enter name: <input type="text" name="customer"/>
<input type="button" value="Set Cookie" onclick="WriteCookie();"/>
</form>
</body>
</html>