Root rot on new blooming Phal?

[AmeliaMay]

Hi,

This is my very first orchid and it was given to me five days ago. I just watered it today as it seemed dry. I've been reading up on orchids all afternoon and would appreciate any advice you can give as I've been unable to find answers to the questions I have.

My main question is about what I should with the roots that are unhealthy - as it is in full bloom (and the flowers are lovely, should I wait for it to finish or trim the roots right away? Should it be repotted? Is there anything else I should do? I've tried to include clear pictures:

Picasa Web Albums - ameliamcmahon - My first orchid!

Thanks in advance!!