You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: bspm_Fcontrasts.m
    path of file: ./repos/bspm/level1
    
    the code of the file until where you have to start completion: function matlabbatch = bspm_Fcontrasts(analysis_dirs, weights, delete_tag)
% BSPM_FCONTRASTS
%
%   USAGE:  bspm_Fcontrasts(analysis_dirs, weights, [delete_tag])
%
%   ARGUMENTS:
%      analysis_dirs: directories containing SPM.mat
%      weights: contrast weights
%      delete_tag: delete existing contrasts: 0 for no (default), 1 for yes
%

% ---------------------------- Copyright (C) 2014 -------------------------
%	Author: Bob Spunt
%	Affilitation: Caltech

    
function matlabbatch = bspm_Fcontrasts(analysis_dirs, weights, delete_tag)
% BSPM_FCONTRASTS
%
%   USAGE:  bspm_Fcontrasts(analysis_dirs, weights, [delete_tag])
%
%   ARGUMENTS:
%      analysis_dirs: directories containing SPM.mat
%      weights: contrast weights
%      delete_tag: delete existing contrasts: 0 for no (default), 1 for yes
%

% ---------------------------- Copyright (C) 2014 -------------------------
%	Author: Bob Spunt
%	Affilitation: Caltech
%	Email: spunt@caltech.edu
%
%	$Revision Date: Sep_23_2014
if nargin<2, mfile_showhelp; return; end