Wireless network extension

Hey all
Somebody should be able to tell me if this'll work
I have some rudementry knowledge of networking and stuff, but wireless is a general murky page for me at present.

I've got Wired ADSL coming into my office and two TP-link TL-WR642G wireless routers.
The idea is to extend the incoming DSL/internet connection out to the shed about 20meters away, (yes i could use UTP, but shed and house two seperate entities with concrete in between)

I've configered the first router with DHCP covering the range 192.168.100.1 to 100. Subnet 255.255.255.0
It automatically found the WAN gateway and works fine for connections plugged into the LAN ports.

BUT how do i configure the second router to detect and connect to the first.

I've got the Same SSID on both. Wireless radio enabled on both
Second router configured DHCP for the ip range 192.168.100.101 to 199.

I've got two computers and three xbox's in the shed to connect to the internet, I'd rather not use static addressing.
I've currently got both routers in the office and trying to connect a second computer to the net via the secound router.

--- = wire
((( = wireless

----ADSL----TPlink-------PC1
((((((((((((((((((())))))))))))))TPlink-----PC2

Any help appreciated.

Ok I've identified the problem.
I need a bridge! and Wireless routers don't generally do a bridge function.
I'm out of luck and need an alternative type of router with aftermarket software to provide WDS (Wireless Distribution Service).
I've asked the manufacturers if they are offering any alternative software as they boast about having sooooo many design engineers and have sooo many products quick to market that they should be able to offer even beta software that only provides a wireless link!