javascript 操作cookies

<SCRIPT type=text/javascript>
function Set(Cookie_name)
{
var Then = new Date()
Then.setTime(Then.getTime() + 1*3600000 ) //小时
document.cookie = Cookie_name+"=true;expires="+ Then.toGMTString()
}
function Get(Cookie_name)
{
var cookieString = new String(document.cookie)
var cookieHeader = Cookie_name+"="
var beginPosition = cookieString.indexOf(cookieHeader)
if (beginPosition != -1) //cookie已经设置值，应该 不显示提示框
{
alert(Cookie_name+"返回"+cookieString.substring(beginPosition + cookieHeader.length));
}
else//cookie没有设置值，应该显示提示框
{
alert("Cookie 未找到!");
}
}
function Move(Cookie_name)
{
document.cookie = Cookie_name+"=;expires=Fri, 02-Jan-1970 00:00:00 GMT";
}
</SCRIPT>
<P><INPUT onclick="Set('Leon')" type=button value=设置cookie值>
<P><INPUT onclick="Get('Leon')" type=button value=查看cookie值>
<P><INPUT onclick="Move('Leon')" type=button value=清除cookie值>
<PRE></PRE>