How do I present randomly the items from two separate sections in one page?

Question

Hi,

I have two separate sections with 72 questions each.
I need to present specific 24 questions from one section and specific 24 questions from the other section in a random order on the same page.

I know how to do it if drawing the questions from one section only.
I tried to adapt the code to draw the questions from both sections (I'm pasting it below).

However, I never get presented all 48 items and I cannot find the error. I can think of that e.g. $questionsNN is not registered as an array, therefore array_merge is inappropriate, and tried to combine it as variables, but that doesn't work either.

Please help!
Thank you in advance.

    if (!isset($questionsNN)) {
  $questionsNN = array(
    'NN01', 'NN02', 'NN11', 'NN12', 
	'NN15',	'NN16', 'NN19', 'NN20', 
	'NN29', 'NN30', 'NN33', 'NN34', 
	'NN37', 'NN38', 'NN47', 'NN48', 
	'NN51', 'NN52', 'NN55', 'NN56', 
	'NN65', 'NN66', 'NN69', 'NN70'
  );
  registerVariable('questionsNN');
}
if (!isset($questionsNQ)) {
  $questionsNQ = array(
    'NQ01', 'NQ02', 'NQ11', 'NQ12', 
	'NQ15',	'NQ16', 'NQ19', 'NQ20', 
	'NQ29', 'NQ30', 'NQ33', 'NQ34', 
	'NQ37', 'NQ38', 'NQ47', 'NQ48', 
	'NQ51', 'NQ52', 'NQ55', 'NQ56', 
	'NQ65', 'NQ66', 'NQ69', 'NQ70'
  ); 
  registerVariable('questionsNQ');
}
if (!isset($NE_all)) {
    $NE_all = array_merge($questionsNN, $questionsNQ);
    shuffle($NE_all);
    registerVariable('NE_all');
}
$ne = loopPage(count($NE_all));
question($NE_all[$ne]);
for ($i=0; $i<count($NE_all); $i++) {
  $id = id('NN75', $i + 1);
  put($id, $NE_all[$i]);
}

Comments

What actually happens (I followed it in the debug window) is that it skips loops.
E.g. it stands loopPage() i=8, and than it shows 9 but quickly skips to 10 without showing the question from page 9.

---

Solved it and changed the code in the original message to the one that works, if somebody needed this ever.