d.frame at parameter usage

Hello,
  I am trying to set up a monitor ( like x1 ) with frames
from a script. I have tried doing d.frame commands as follows.
  I interactively did d.mon and dragged the window up to cover
most of the screen, with the mouse. I then tried to give the following
statements either in a script, or manually, in the same form, i.e. each
on its own single line.
d.frame -c frame=full_screen at=1,679,1,961
d.frame -c frame=title1 at=275,320,1,295
d.frame -c frame=title2 at=320,365,1,295
d.frame -c frame=legend at=365,679,1,295
and I get errors on the at parameter. Why?

Also, is there a way to get the d.mon provided window sized
automatically, i.e. without benefit of mouse interaction?

Thanks,
Joe Vaughan