Need help finding correct cable for modem (2Wire 3600HGV)

I need a cable(50ft-75ft) that goes from the phone jack in the wall to the 2Wire modem.

I bought this cable at Amazon and it didn't work: http://www.amazon.com/OEM-Telephone-Phone-Extension-Cable/dp/B004BOPZ8S/ref=sr_1_11?s=electronics&ie=UTF8&qid=1360970913&sr=1-11

That cable fit in the phone line slot behind the modem but it didn't work.  The lights on the front of the modem would just keep blinking.

I want to move my modem to a different room.  Can someone tell me what this cable is called that I'm looking for or link me to a site where I can buy one?  I need one at least 50ft.  75ft would be better.

Thank you.