两种存储方式localStorage和sessionStorage，由cookie完成。
localStorage：没有时间限制：
if (localStorage.pagecount)
{
localStorage.pagecount=Number(localStorage.pagecount) +1;
}
else
{
localStorage.pagecount=1;
}
document.write("Visits "+ localStorage.pagecount + " time(s).");
sessionStorage：针对一个session：
if (sessionStorage.pagecount)
{
sessionStorage.pagecount=Number(sessionStorage.pagecount) +1;
}
else
{
sessionStorage.pagecount=1;
}
document.write("Visits "+sessionStorage.pagecount+" time(s) this session.");
原文：http://www.cnblogs.com/wang-jing/p/4095905.html