tfboys穿越超少年密码:javascript中如何获取cookies?

<script type="Text/javascript">
/**
* Sets a Cookie with the given name and value.
*
* name Name of the cookie
* value Value of the cookie
* [expires] Expiration date of the cookie (default: end of current session)
* [path] Path where the cookie is valid (default: path of calling document)
* [domain] Domain where the cookie is valid
* (default: domain of calling document)
* [secure] Boolean value indicating if the cookie transmission requires a
* secure transmission
*/
function setCookie(name, value, expires, path, domain, secure) {
document.cookie= name + "=" + escape(value) +
((expires) ? "; expires=" + expires.toGMTString() : "") +
((path) ? "; path=" + path : "") +
((domain) ? "; domain=" + domain : "") +
((secure) ? "; secure" : "");
}

/**
* Gets the value of the specified cookie.
*
* name Name of the desired cookie.
*
* Returns a string containing value of specified cookie,
* or null if cookie does not exist.
*/
function getCookie(name) {
var dc = document.cookie;
var prefix = name + "=";
var begin = dc.indexOf("; " + prefix);
if (begin == -1) {
begin = dc.indexOf(prefix);
if (begin != 0) return null;
} else {
begin += 2;
}
var end = document.cookie.indexOf(";", begin);
if (end == -1) {
end = dc.length;
}
return unescape(dc.substring(begin + prefix.length, end));
}

/**
* Deletes the specified cookie.
*
* name name of the cookie
* [path] path of the cookie (must be same as path used to create cookie)
* [domain] domain of the cookie (must be same as domain used to create cookie)
*/
function deleteCookie(name, path, domain) {
if (getCookie(name)) {
document.cookie = name + "=" +
((path) ? "; path=" + path : "") +
((domain) ? "; domain=" + domain : "") +
"; expires=Thu, 01-Jan-70 00:00:01 GMT";
}
}
</script>
<INPUT TYPE="submit" style="button" value="ClearCookie" onclick='deleteCookie("name");return false;'><BR>
<INPUT TYPE="submit" style="button" value="SetCookie" onclick='setCookie("name", "Jason Davies");return false;'><BR>
<INPUT TYPE="submit" style="button" value="GetCookie" onclick='alert(getCookie("name"));'><BR>

function setCookie(name,value) {
var today = new Date();
var expires = new Date();
expires.setTime(today.getTime() + 1000*60*60*24*365);
document.cookie = name + "=" + escape(value) + "; expires=" + expires.toGMTString();
}

function getCookie(Name) {
var search = Name + "=";
if(document.cookie.length > 0) {
offset = document.cookie.indexOf(search);
if(offset != -1) {
offset += search.length;
end = document.cookie.indexOf(";", offset);
if(end == -1) end = document.cookie.length;
return unescape(document.cookie.substring(offset, end));
}
else return('');
}
else return('');
}