quizz with wmlscript

I'm trying to figure out how to score a quizz using wmlscript. I have the correct/incorrect answer part working, I'm trying to create a function that keeps score by incrementing the value of a variable, I'm not sure what I'm doing wrong.

the script:

function addscore(){
var points;
points=points++;
return points;
}

extern function validateAnswer(Answer)
{
var validResponse = WMLBrowser.getVar("Answer");
if (validResponse != "value")
{
WMLBrowser.go("poll2.wml#NResults");
}
else
{
WMLBrowser.go("poll2.wml#YResults1");
var number = addscore();
WMLBrowser.setVar("score", number);
}
};

extern function validateAnswer2(Answer){
var validResponse = WMLBrowser.getVar("Answer");
if (validResponse != "value")
{
WMLBrowser.go("poll2.wml#NResults");
}
else
{
WMLBrowser.go("poll2.wml#YResults3");
var number = addscore();
WMLBrowser.setVar("score", number);
}
};

The card that's supposed to show the score:

<card id="YResults3" title="Results:">
<p>
Yes: Answer $(Answer) is correct "
</p>
<p>
Score: $(score) out of 3 "
</p>
<p>
<a href="poll2.wml#Trivia1">Start Over</a>
</p>
</card>

I would make sure of two things:

(1) That you have the correct initial value of points in the addscore function, and

(2) That you are calling the addscore function before you go to the YResults3 card.