Mattlabbatch and using an optional variable

Hello,

I am running a batch job using matlabbatch and it works when I have both T1w and T2w as input variables. Now I want to make it so that the code will run just T1w variables. However, I have made the T2w variable run matlabbatch{2} only if the T2w variable exists. However, I am still getting an error the last line of the code, saying that the inputted job is not a valid job. Do you have any suggestions?

Here is the code:

% realign data
matlabbatch{1}.spm.spatial.realign.estwrite.data = {{timeseries}};
matlabbatch{1}.spm.spatial.realign.estwrite.eoptions.quality = 0.9;
matlabbatch{1}.spm.spatial.realign.estwrite.roptions.prefix = 'r';
meta.realign.reference     = 'mean';
meta.realign.interpolation = '4th degree B-spline';
% coreg T2w to T1w
if exist('T2w', 'var')
    matlabbatch{2}.spm.spatial.coreg.estwrite.ref = {T1w};
    matlabbatch{2}.spm.spatial.coreg.estwrite.source = {T2w};
    matlabbatch{2}.spm.spatial.coreg.estwrite.other = {''};
    matlabbatch{2}.spm.spatial.coreg.estwrite.eoptions.cost_fun = 'nmi';
    matlabbatch{2}.spm.spatial.coreg.estwrite.eoptions.sep = [4 2];
    matlabbatch{2}.spm.spatial.coreg.estwrite.eoptions.tol = [0.02 0.02 0.02 0.001 0.001 0.001 0.01 0.01 0.01 0.001 0.001 0.001];
    matlabbatch{2}.spm.spatial.coreg.estwrite.eoptions.fwhm = [7 7];
    matlabbatch{2}.spm.spatial.coreg.estwrite.roptions.interp = 4;
    matlabbatch{2}.spm.spatial.coreg.estwrite.roptions.wrap = [0 0 0];
    matlabbatch{2}.spm.spatial.coreg.estwrite.roptions.mask = 0;
    matlabbatch{2}.spm.spatial.coreg.estwrite.roptions.prefix = 'r';
end
% segment T1w/rT2w
matlabbatch{3}.spm.spatial.preproc.channel(1).vols = {T1w};
matlabbatch{3}.spm.spatial.preproc.channel(1).biasreg = 0.001;
matlabbatch{3}.spm.spatial.preproc.channel(1).biasfwhm = 60;

% threshold tissue maps at 70% making them binary images
matlabbatch{4}.spm.util.imcalc.input(1) = cfg_dep('Segment: c1 Images', substruct('.','val', '{}',{3}, '.','val', '{}',{1}, '.','val', '{}',{1}), substruct('.','tiss', '()',{1}, '.','c', '()',{':'}));
matlabbatch{4}.spm.util.imcalc.output = 'desc-GM_thresh70';
matlabbatch{4}.spm.util.imcalc.outdir = {destination};
matlabbatch{4}.spm.util.imcalc.expression = 'i1>0.7';
matlabbatch{4}.spm.util.imcalc.var = struct('name', {}, 'value', {});
matlabbatch{4}.spm.util.imcalc.options.dmtx = 0;

% coregister T1w to meanEPI and apply to thresholded tissue images
matlabbatch{7}.spm.spatial.coreg.estwrite.ref(1) = cfg_dep('Realign: Estimate & Reslice: Mean Image', substruct('.','val', '{}',{1}, '.','val', '{}',{1}, '.','val', '{}',{1}, '.','val', '{}',{1}), substruct('.','rmean'));
matlabbatch{7}.spm.spatial.coreg.estwrite.source = {T1w};
matlabbatch{7}.spm.spatial.coreg.estwrite.other(1) = cfg_dep('Image Calculator: ImCalc Computed Image: desc-GM_thresh70', substruct('.','val', '{}',{4}, '.','val', '{}',{1}, '.','val', '{}',{1}), substruct('.','files'));
matlabbatch{7}.spm.spatial.coreg.estwrite.other(2) = cfg_dep('Image Calculator: ImCalc Computed Image: desc-WM_thresh70', substruct('.','val', '{}',{5}, '.','val', '{}',{1}, '.','val', '{}',{1}), substruct('.','files'));
matlabbatch{7}.spm.spatial.coreg.estwrite.other(3) = cfg_dep('Image Calculator: ImCalc Computed Image: desc-CSF_thresh70', substruct('.','val', '{}',{6}, '.','val', '{}',{1}, '.','val', '{}',{1}), substruct('.','files'));
matlabbatch{7}.spm.spatial.coreg.estwrite.eoptions.cost_fun = 'nmi';
matlabbatch{7}.spm.spatial.coreg.estwrite.eoptions.sep = [4 2];
matlabbatch{7}.spm.spatial.coreg.estwrite.eoptions.tol = [0.02 0.02 0.02 0.001 0.001 0.001 0.01 0.01 0.01 0.001 0.001 0.001];
matlabbatch{7}.spm.spatial.coreg.estwrite.eoptions.fwhm = [7 7];
matlabbatch{7}.spm.spatial.coreg.estwrite.roptions.interp = 4;
matlabbatch{7}.spm.spatial.coreg.estwrite.roptions.wrap = [0 0 0];
matlabbatch{7}.spm.spatial.coreg.estwrite.roptions.mask = 0;
matlabbatch{7}.spm.spatial.coreg.estwrite.roptions.prefix = 'r';
out = spm_jobman('run',matlabbatch);

Here is the error:

No valid job.

out = spm_jobman('run',matlabbatch);