check if time is more than 24 hours

hi experts

I have a table Customer which has columns

ID   Name   LastLoggedIn   LoggedInstatus

LastLoggedIn is a timestamp column


I want to come up with a sql which checks
if current time - LastLoggedIn > 24 hours  THEN
update Customer set LoggedInstatus = false

basically the point is if customer is logged in more than 24
hours set the LoggedInstatus  to false

trying to come up with sql , doesnt seem like working

update Customer set LoggedInstatus = false
where
select customer.LastLoggedIn - GETDATE()  from Customer customer  > 24

any help will be appreciated..

thanks.