truemobile 2003 problem integrating with existing network

Here is my problem.  Currently I have a linksys router that's connected to a dsl modem with 3 other computers and is set on dhcp.  I want to integrate my new truemobile 2003 router into the existing network so I can share the same local network wirelessly on my laptop.  This is what I tried doing:

1) I changed the wireless router setting to access point and assigned an ip to the wireless router.   The ip I assigned was the ip that showed on my old router's dhcp table.  Then I plugged an ethernet cable from the old router's uplink port to one of the lan port on the wireless router.  I also disabled dhcp on my wireless router.   After doing all this, my laptop is unable to connect online. 

I already tried reading this link http://docs.us.dell.com/docs/network/p57205/en/ex_confg/ex_netwk.htm but all the steps I have done already.  Does anyone know what's wrong?? Plz help me