% Purpose
%    gets time axis value from data file. Return format YYMMDDhhmmss.fff.
%
% Synopsis
%    time = mexeps('gettaxis',varcode)
%    time = mexeps('gettaxis',varcode, ax_range)
%
% Description
%    It returns value of time axis of a variable from the data file. 
%    The variable is refered to by variable code, varcode. The ax_range 
%    is optional. If ax_range is not specified, all values will be 
%    returned; otherwise, ax_range is a 1x2 array contains [lower upper] 
%    limits of the time axis you want to get.  The output time value
%    is in the format of YYMMDDhhmmss.fff.  For example, April 15, 1994
%    13:24:00 will be 940415132400.000. (Use gettaxis2 to get time format
%    YYYYMMDDhhmmss.fff.)
%
% Examples
%    Open a data file and get time axis value of first variable.
%
%      currentfile = mexeps('openr','datafile.cdf');
%      var_list = mexeps('varlist');
%      varcode = var_list(1); 
%      time = mexeps('gettxis',varcode)
%      ...
%
% See Also
%    gettaxis2, getaxis
%