php update multiple records using checkboxes

how do i get a record update form to update multiple records, where the records
that have to be updated are selected by marking a checkbox?

i''ve already found some feedback on how to do this in asp, but i haven't come
over anything useful in php

all suggestions are extremely welcome... i'm very close to banging my head on
my desk

does anyone know whether this is pssible at all?
thanks a lot in advance