Networking issues

We have a small office with about 6 computers. They used to be connected through a wired router, but recently switched over to a wireless. The two computers that are laptops connect to the network when hooked up through their ethernet cables, but when i attempt to use them away from their desks through the WLAN they read the wireless signal, but won’t recognize the internet gateway. I messed around with the IP address and settings to the best of my knowledge, but have hit a stand still…any ideas? My own personal laptop that was never hooked into the system until the wireless router connects just fine. Any tips would be great!!!