'96 Pace Arrow window problem....

After being fulltimers since this 'ol buss was new we have settled down to house living for a while. Now the trips are for the winter to S.TX. for five or six months. Now to the problem. Not knowing much about windows or glazeing as I guess it's called I need some guidance. The gaskets?,for lack of a better word, or tracks that the window glass sets in has started to crack, split and otherwise deteoriate to the point that I'm afraid it's leaking. These are the slideing windows, single pane from the last century that everyone used to use. How do I fix this? Ecconomicly? Myself, maybe???? Should I post up a pic or two, or has this already come up, I did a search or two and couldn't find anything relative........ Thanks!!!!