How do I Use XML attributes?

Hi every one, sorry from my english I'm from spain. I'm making a multilingual quiz wich questions appair randomly. I'm storing texts from some XMLs, this is the structure:

<ques>

<q>question</q>

<op>option1</op>

<op>option2</op>

<op correct=true>option3</op>

<ques>

I want to use the atribute correct to set te correct answer because the correct answers is not always the third obviusly. How can I do that or is there an other way to make easier to set the correct question?

Thanks you every one

Here is an example of simple quiz depends on XML

I used this xml

<?xml version="1.0" encoding="utf-8"?>

<questions>

<question no="1">

<title>Capital of France</title>

<correct>3</correct>

<answer>Lyon</answer>

<answer>Marseille</answer>

<answer>Paris</answer>

</question>

<question no="2">

<title>3x2</title>

<correct>2</correct>

<answer>5</answer>

<answer>6</answer>

<answer>7</answer>

</question>

</questions>

If you change global variable you can skip to other questions

Thank you