function indx = indxfn( tval, tvec )
%--------------------------------------------------------------------------
%
% PURPOSE: Find the time index
% FIRST AUTHOR:  Rob McEwen
% DATE:    05/2/11
% CHANGE LOG:  Date    Name    Comment
%         (1)
%
%--------------------------------------------------------------------------
%
  indxup = find(tvec > tval);
  indxdn = find(tvec < tval);
  indx = indxup(1);
