Quiz gotoFrame correct answer..problem

hello i have a simple quiz question,i just can’t quite seem to get right.

i have been learning AS2.0 through modifying scripts to get a better understanding ,here’s the some what original script

this.stop();

mcSubmit.onRelease = function():Void {
calculateScore();
};

_global.style.setStyle(“color”, “white”);
_global.style.setStyle(“themeColor”, “red”);
_global.style.setStyle(“fontSize”, “14”);
_global.style.setStyle(“fontFamily”,“Arial”);
_global.style.setStyle(“fontWeight”,“bold”);

function calculateScore():Void {
var bScoreOne:Boolean = (kindofdog.selectedData == “cat”);
var bScoreTwo:Boolean = (trained.selectedData == “No sir”);
var bScoreThree:Boolean = (playset.selectedData == “three”);
var fScore:Number = 0;
if(bScoreOne) {
fScore++;
}
if(bScoreTwo) {
fScore++;
}
if(bScoreThree) {
fScore++;
}
this.nextFrame();
tQuizScore.text = “You scored " + fScore + " correct out of 3 questions.”;
}

/////////// END /////////

which is fine…BUT how do i tell the script to goto different frames depending on the value (how many question you got right)
shouldn’t it read it read after the last line

/// BUT if you get " 3 out of 3 " questions correct goto frame 20 //////

        if  (nScore:Number = 3 
tQuizScore.text = "You scored " + fScore + " correct out of 3 questions.":
        GotoFrame 20();

what am i not understanding that this is wrong???

any help would be great thanx