The problem that you have is your have bought a switch.  A switch will not work.  You should have bought a router.  e.g. Netgear DG834.  So that is what you need to do buy a router.
If you modem does not have an Ethernet output you may be better off buying a router with a built-in Modem.  In fact they are better anyway as they are much easier to set up.
                
 t
                
 September 2007