how can I get different sessionID(windowID) in chrome Incognito mode?

I open a chrome incognito mode window(ctrl+shift+n), and log in: https://www.google.com/accounts/ManageAccount

now ,I want login another account开发者_开发百科, I open a new incognito mode window,

but the new window is already logined for last account,

how can I get different windowsID in chrome Incognito mode?

BTW: google.com only a example, I want login another sites,like stackoverflow.com, so ,I want get a different windowID in new chrome window

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Isn't it possible to avoid the problem altogether by going to your Account Settings and changing "Multiple sign-in" ?

This would allow you to login to multiple accounts in most Google products.

Here's another interesting link: "Using multiple accounts simultaneously" on Google's own online help.