PHP adding to sessions - php

Question

I am making an online quiz, in this quiz, one question is asked at a time. If the answer is correct, I want to add that point, to the total score earned. I want the $_SESSION to show how many points the user has earned so far. The code I have so far is this:
$sql = "SELECT * FROM quiz_questions WHERE Question='$question' AND Answer='$answer'";
$result = mysql_query($sql);
$num_rows = mysql_num_rows($result);
if ($num_rows != 0){
$score++;
$total_score += $score;
session_start();
$_SESSION['score'] = $total_score;
} else {
echo "Incorrect";
}
}
I already have $score equal to 0 to start in the beginning of the code. Thank you in advance for all your help!

Answer 1

session_start(); // should be at the beginning of your script(s);
if (!isset($_SESSION['score'])) { $_SESSION['score'] = 0; }
$sql = "SELECT * FROM quiz_questions WHERE Question='$question' AND Answer='$answer'";
$result = mysql_query($sql);
$num_rows = mysql_num_rows($result);
if ($num_rows != 0){
// $row = fetch row to get the actual score for this question, if answered right?
$row = mysql_fetch_row($result);
//$score++; ??????
//$total_score += $score;
$_SESSION['score'] += $row['score_index'];
//$_SESSION['score']++; // or just this, dunno
echo 'Your current score is: '.$_SESSION['score'];
}
else {
echo "Incorrect";
}