usually there is some server side script involved in login feature (you would need to somehow validate user credentials, right?). But if you skip server side section you could use flash.net.SharedObject to *session* login data between your applications. If for example there is no information in SharedObjet about user login and it for example expires (if you store data hash in SharedObject too) - you could navigate back to login page I think.
Here is tutorial which uses states within the same application to provide such feature:
Why are there 2 applications at the first place... you should have a popup/page at the start which is ur
login followed by the welcome screen... All this should be in 1 App
Thanks for your response. Earlier i had only 1 application and i was using different states. but the problem is once a user is login and he is in home page and due to some reason if user refresh the browser login screen is getting displayed.
Could you please tell me how can i solve this problem