I'm developing an embedded web server. Now, I've an access validation page (e.g. in the beginning that accepts password and validates it and then redirects the customers towards the actual device control web site ( I don't want the particular hyperlink to show up on the address bar. Rather the first url ought to be maintained to ensure that customers cannot directly visit this site nor have the ability to bookmark this site....I realize this should be a typical requirement but tend to not find any sort of solutions for this...any help / references could be greatly appreciated....Thanks ahead of time.

That isn't possible with Javascript alone. Make use of a Frameset (or maybe you are using Apache have a look in the mod_rewrite module).

Yet another advice: Do not do it! I'd leave your website immediately, after i click around and also the URL does not change. Appears like you are hiding something.