How to save multiple data in one text file

I want to save height and width value from multiple objects in one text file, but it only saved the last processed image data. here's my code:

contents = get(hObject,'Value')
pilih=guidata(gcbo);
theImage{1}=getImage(handles.axes1);
theImage{2}=getImage(handles.axes2);
theImage{3}=getImage(handles.axes3);
theImage{4}=getImage(handles.axes4);
theImage{5}=getImage(handles.axes5);

for z = 1:5;
    Img = theImage{z};
    abu=rgb2gray(Img);
    cb=imclearborder(abu);
    thresh=graythresh(cb);
    b=im2bw(cb,thresh);
    bw=bwareaopen(b,60);
    bwfill=imfill(bw,'holes');
    s=regionprops(bwfill,'BoundingBox');
    objects=cell(numel(s),1);
    for idx=1:numel(s)

          bb=floor(s(idx).BoundingBox);
          out=bsxfun(@times,Img,uint8(bwfill));
          objects{idx}=out(bb(2):bb(2)+bb(4),bb(1):bb(1)+bb(3),:);
      end
          X = zeros(3, numel(objects));
              for k = 1:numel(objects)
                  k1=objects{k};
                  c1=rgb2gray(k1);
                  t1=graythresh(c1);
                  biner1=im2bw(c1,t1);
                  [height,width]=size(biner1);
                  a1=bwarea(biner1);
                  X(:,k)=[height;width;a1];
              end
  end

save grading/datauji.txt X -ascii;

What should I do? Thank you very much.