## This takes a selection and fits that selection for every frame in the
## molecule (all atoms are moved, but the fit is based on the selection).
## 
## For example:  fitframes top "protein"
## 
## -Jim
proc fitframes { molid seltext } {
  set ref [atomselect $molid $seltext frame 0]
  set sel [atomselect $molid $seltext]
  set all [atomselect $molid all]
  set n [molinfo $molid get numframes]
   
  for { set i 1 } { $i < $n } { incr i } {
    $sel frame $i
    $all frame $i
    $all move [measure fit $sel $ref]
  }
  return
}