NAME
        TracePick

   DESCRIPTION
        This module is used to get pick information to send to the TraceLat and 
        TraceInfo modules

   INPUTS

      Input Pick -- Pick
         Picked input from the render module.  Select pick and user pick mode
         in the render. Place cursor on track and click left mouse button.  Try to only
         chose one track at a time.

   WIDGETS

      TraceInfo -- Radio Box
         (Display Information only, Display hits on picked trace, Do not display trace, Reset display).
         This lets the user select what happens to the picked track.  "Display
         information only" will cause information to appear in the TraceInfo window.
         "Display hits on the picked trace" will also put blue crosses on the hit points
         for that trace.  "Do not display trace" is useful in eliminating traces which
         look strange because heavy curvature combined with a maxinum number of steps in
         a region without many detectors.  The D0 geometry is especially prone to this
         effect.  The symptom is tracks that look as if they were draw by a spirograph.
         "Reset Display" allows the user to undo the effects of the picking.

   OUTPUTS

      HepNumber -- Parameter
         Hep number of the track that was picked.  Sent to TraceLat and TraceInfo

      TraceInfoOut -- Parameter
         Outputs the setting of the TraceInfo Widget to TraceLat

   KNOWN PROBLEMS
      Sending HepNumber and TraceInfoOut separately to TraceLat seems to cause
      multiple firing.  Patience is required when using the pick option in this way.

   SEE ALSO
      TraceLat
      TraceInfo
      Render