js取cookie里面的一个值

function getCookie(sName)
{
var aCookie = document.cookie.split("; ");
for (var i=0; i < aCookie.length; i++)
{
var aCrumb = aCookie[i].split("=");
if (sName == aCrumb[0])
return unescape(aCrumb[1]);
}
return null;
}

var name=getCookie(name)/*sName为要取的key名*/