attaching entities information contexts

in linq sql, illusory check an entity already biased information context before perplexing insert it?

a small context helps...

i have formula global.asax supporter method. normally, between requests, isn't problem. nonetheless right after signing in, removing called some-more once, second i finish adult perplexing insert member vigilant same section work where created.

private vacant checkcurrentuser()
{
    (!httpcontext.current.user.identity.isauthenticated)
    {
        apphelper.currentmember = null;
        return;
    }

    iuserservice userservice = new userservice();

    (apphelper.currentmember != null)
        userservice.attachexisting(apphelper.currentmember);
    else
        apphelper.currentmember = userservice.getmember(
            httpcontext.current.user.identity.name,
            apphelper.currentlocation);
}