Macbook wirless configuration modem only works with ethernet cable need wireless to work what do I need to do?

  Hello:
         I am working with a Macbook intel dual processor. I am able to use internet with Konqueror with ethernet cabe attachment, although, I am not able to use the wireless connection that comes built in on this computer. I am pretty certain it is a hardware confiquration problem...what software or other browser do I need to install.
I am able to enabale wireless modem in panel it still has no effect and I recieve an error message cannot access internet or something to some such effect. Do your best to see me through this one!
                                                                                                                                                                                                                   Thanks,
                                                                                                                                                                                                                    Mitchell