Hardware firewall and router trouble

i currently have a linksys wireless router. i recently purchased a dlink dfl-700 hardware vpn firewall. i want to place the hardware firewall between my cable modem and the wireless router. i set both to factory defaults (router and firewall) then connected a cable from the cable modem to the WAN port of the firewall and a cable from the LAN port of the firewall to the WAN port of the router with no luck then removed the cable from the WAN port of the router and placed it in the LAN port of the router and still nothing. how to i connect both and get internet access?