How do I get the sum of my variables and display the total?

I have written out a quiz and have each button setting a variable, example: http://www.kreativitydesigns.com/Clients/Globus/Monograms/MBA_Test/del iverables/MBA_Quiz.html?mode=preview

However, when it hits the "Grade" frame to calculate and display the total, it is not displaying. 

I do have the text box named "Grade" on stage and the variables have all been given a value before entering this frame

Here is the code used to calcualte and output the result:

//get the value of a variables and store them

var FinalScoreHolder = q1 + q2 + q3 + q4 + q5 + q6 + q7 + q8 + q9 + q10 + q11 + q12 + q13 + q14 + q15 + q16 + q17 + q18 + q19 + q20 + q21 + q22 + q23 + q24 + q25 + q26 + q27 + q28 + q29 + q30 + q31 + q32 + q33 + q34 + q35 + q36 + q37 + q38 + q39 + q40;

//Display the Grade

sym.$("Grade").html("You scored "+FinalScoreHolder+"%");

//Show Result Page

if (FinalScoreHolder >= 89) {

// play the timeline from the given position (ms or label)

sym.play("pass");

} else {

// play the timeline from the given position (ms or label)

sym.play("fail");

}

Any help would be greatly appreciated.

Thanks!