desktop internet sharing to laptop

desktop internet sharing to laptop
here’s the situation:
ihave laptop and a desktop. the desktop has an access to internet. it has two lan card, one is for the dsl modem. and the other one is connected to the laptop wired lan. i connect them using a crossed cable and they see each other in the network. the laptop is wifi ready. the problem is, i can’t able to share the internet from desktop to laptop. i enabled the internet connection sharing of desktop but not work. can you help me on how to configure the internet sharing. both pc using windows xp. tnx