How clientscript member Authentication last the whole browse session than a page

I use asp.net ajax client method to do member Authentication

Sys.Services.AuthenticationService.login(username.value,password.value, true ,null,null,null,null,"User Context");

It successed in current page. but when I redirecit to another page, the Authentication dissapeard

How clientscript member Authentication last the whole browse session

I found I have wrong setting in my config files