(Urgent!) Allow members enter only (oscommerce)

Hi, I need an extreme simple index page to limit our Oscommerce shop. Urgent! You need finish it in 2 hours! The path of my shop is: [login to view URL] (I changed "catalog" to "shop" I need a very simple index page which only include extreme simple login box (no new account create function). I don't want new customers any more. The purpose is: I need allow members to see my shop and don't allow guest to enter in. Don't allow register. Even if the guest visit the link: [login to view URL], the guest can't see my shop. Repeat again, I only allow existing customer to see the shop. You just finish it and show me the demo, then I will install by myself. Don't bid high price, this is a very simple job! Thanks