Using RAW+JPEG stacking script, but can't get JPEG as default thumbnail for stack. Help!

Question

I am currently using this script I found elsewhere on Adobe forums. However, doing this function only will stack everything with the raw files on top. I am using a 5D MKIII now and Bridge CS4 can't generate the CR2 previews, so I need JPEGs to see what a file is for general editing. How do I get this stack script to put the JPEGS on top instead of the raw files?
(script originally posted by Paul Riggot in another forum)
#target bridge  
   if( BridgeTalk.appName == "bridge" ) { 
AutoStack = MenuElement.create("command", "Auto Stack", "at the beginning of submenu/Stack", "zx1");
AutoStack.onSelect = function () {
   stackEm();
function stackEm(){
app.document.sorts = [{ name:"name",type:"string", reverse:false}];
var jpgs = Folder(app.document.presentationPath).getFiles ("*.jpg");
app.document.deselectAll();
for(var a in jpgs){
var Name = decodeURI(jpgs[a].name).replace(/\.[^\.]+$/, '');
var stacks = Folder(app.document.presentationPath).getFiles(Name+".*");
if(stacks.length < 2) continue;
for(var z in stacks){ app.document.select(new Thumbnail(stacks[z]));}
StackFiles();
app.document.deselectAll();
function StackFiles(){
app.document.chooseMenuItem('submenu/Stack');
app.document.chooseMenuItem('StackGroup');

Answer 1

I wonder if you have time if you could test this script for me please?
What it does (tries to do) is to create JPGs from the raw files in the same folder as the CR2 (raw) files.
N.B. IT WILL OVERWRITE ANY JPGS IN THE SAME FOLDER IF THE NAMES MATCH!
So please try it on a folder with raw files only.
The idea being it might be quicker to generate jpegs from the embedded thumbnail rather than shoot both raw/jpg?
T.I.A.
#target bridge  
if( BridgeTalk.appName == "bridge" ) { 
AutoStackJpgs = MenuElement.create("command", "Create Stack JPGs", "at the beginning of submenu/Stack", "sj1");
AutoStackJpgs .onSelect = function () {
app.document.deselectAll();
var items = app.document.getSelection("crw,cr2,tiff,raw,rw2,dng,nef,orf,erf,mos,dcr,raf,srf,pef,x3f");
for (var a =0; a<items.length;a++){
var JPEG = new File(items[a].path.substr(0,items[a].path.lastIndexOf ('.'))+".jpg");
tempFile=new File(items[a].path);
var fileString='';
tempFile.open('r');
tempFile.encoding = 'BINARY';
fileString=tempFile.read();
tempFile.close();
for(var w =0;w<6;w++){
var startJpg=fileString.search(/\xFF\xD8\xFF/);
if(startJpg != -1){
if(testJPG()){
var endJpg = fileString.search(/\xFF\xD9/);
fileString = fileString.substr(0,endJpg+2);
JPEG.open('w');
JPEG.encoding = 'BINARY';
JPEG.write(fileString);
JPEG.close();
var newThumb = new Thumbnail(JPEG);
newThumb.rotation = items[a].rotation;
break;
}else{
fileString = fileString.substr(20);
continue;
function testJPG(){
var result=false;
fileString = fileString.substr(startJpg);
var endTest = fileString.search(/\xFF\xD9/);
if(endTest > 204800 ? result= true : result= false);
return result;