Two routers, one network

I had two routers, an old wired one and a wireless one. The wireless one is the one connected to the internet, and I want to connect a couple of computers in a different room using the second router as a LAN. The older one (D-Link DI-604) doesn't have a "client mode" (i.e. will automatically work as an extension) so need to do some work. Was a bit of hassle to get working, as I'm not a network expert.

This diagram shows the arrangement to get it working. The following notes are how to plug a router into an existing (working) router:

• Router B should be added as another client on the LAN, and the output of router A is a LAN input on B (i.e. not the WAN input).
• Give router B a valid static address on the subnet of A. So if a has mask 255.255.255.0 and an IP 192.168.1.1 and a DHCP range of 192.168.1.100 to 192.168.1.200 you are free to give router B an IP of 192.168.1.210.
• Disable DHCP on router B. Force the DHCP lease to renew on clients plugged into it if they won't connect.

And bingo, it should work! You lose two LAN ports, but this the only way I could get it to work.