– if you don’t already have a wireless PCMCIA card for the laptop you can buy one for about $30 at most computer stores.
– install the software & card into PCMCIA slot on the laptop
– you should see the Airport network in your list of networks; however, if you have encryption on the Airport it might get trickier.
– essentially, if you want to protect your network with encryption, you can try to get the laptop to work with either the 40-bit or 128-bit options of the Airport– they are not all compatible and you may have to enter the encryption string in HEX characters.
( see http://docs.info.apple.com/article.html?artnum=108058 )
If this doesn’t work, as a work around you can disable the encryption on the network and instead use the “Access Control” list feature in Airport to restrict the Airport to only the computers that use it. This is done by adding the computers Ethernet ID, a 10-digit hex code, to this list in the Aiport Admin Utility.