There is a header Max-Age that allows to specify the expiration time of a cookie. Unfortunately Internet Explorer 6, 7, 8 and probably later do not support Max-Age and requi
From QuirksMode
function readCookie(name) {
var nameEQ = name + "=";
var ca = document.cookie.split(';');
for(var i=0;i < ca.length;i++) {
var c = ca[i];
while (c.charAt(0)==' ') c = c.substring(1,c.length);
if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
}
return null;
}
Then after you get the cookie name
and maxAge
and otherOptions
(e.g. path, domain) from somewhere:
var date = new Date();
date.setTime(date.getTime() + (maxAge * 1000));
document.cookie = name + "=" + readCookie(name) +
'; expires=' + date.toUTCString() + otherOptions