It's quite possible, although it depends on the wireless capability of the iMacs. To find out, boot them up and see if there's an Airport menu on the menubar. If not, it's highly unlikely that the computer is wireless-capable.

To solve the problem, you could buy an Airport Extreme card for any iMacs that do not have Airport already. They're $50 if you're interested:
http://store.apple.com/1-800-MY-APPL...More=M8881LL/A

Alternatively, you could save yourself about $30 and buy yourself a USB Wireless adapter, which although would cut down the speed a bit, requires no installation.

Finally, once the iMac has wireless, you can connect to your D-Link router by using the Airport menu to choose the network to connect to. Simply enter your password (if needed), and you're done.

Thank you Joeprogrammer. The USB wireless adapter that you mentioned, we have with us 3 of these: D-Link DWL-G122 External USB adapter, which we put on some PCs. Can this kind work on the Macs?

Thanks again.

Not according to D-Link's site:

http://www.digitalhome.com.au/Comput...B_Adapter/1642
[edit] Apparently it is possible to use it on a Macintosh by using the Ralink Technology drivers. See this how-to for more information:
http://www.macosxhints.com/article.p...50201091946184

Many thanks for the valuable information. I shall give it a try. I wonder if anybody has done it: installing Ralink driver and use the D-Link G122 USB for the Mac.

Perfect ,it's very good.

I'm happy to say I did it...took a little time to work through it but now I get it thank you for your help ...