Problem connecting Linksys wireless router & Terayon modem?

I've never had issues with this router until now. I've had it for about 3 years & I recently got a new cable provider & I can't seem to get internet to run from my modem (Terayon TJ715) to my Linksys G-Broadband router (WRT54G). When I go to connect to it it says "no internet access" in italics. Any idea of what the problem might be & how I can fix it? Thank you so much for your time.