Homebrew PCBs

Thanks Phil, Javaguy and Rusty for the tips with Eagle.  The via 
thing was so simple, I didn't even think of doing it.
  I have another one for you.  I've read the manual and didn't see 
it.  You'll probably slap me for being ignorant, but here goes:

  How do you change the width of the tracks the autorouter uses?  I 
have tried changing the line width before using the autorouter, but 
it sticks to the line size it appears to like best.  If I group all 
the traces and use the change tool after they're drawn, I get 
overlapping lines if they get too big.
  How can I specify lines with big width before routing, so the 
autorouter doesn't overlap them?

Thanks very much for the help

Josh
Pullman, WA