Quiz scripting help, please

programming flash
1

So I have this quiz that has a dynamic box for the question and answer and 3 checkboxes that have option1, option2 and option3 for their names. So how can I have it that if a user checks one box and then checks another the first boz gets unchecked? As well if the user selects the right answer the answer box says “Correct” and displays the “next” button to proceed. Lastly if they select the wrong button, the answer box says "Try agian. I’ve included my code:

stop();

nextButton.addEventListener(MouseEvent.MOUSE_DOWN, goNext);

updateView();
nextButton.visible = false

function goNext(e:MouseEvent):void
{

if(currentFrame != this.numFrames){
    if(getAnswer() == true){
        //The user was right
        answer.text = "Correct Answer!";
        nextButton.visible = true
        ;
    }else{
        //The user was wrong
        answer.text = "Wrong! Try again";           
    }       
    nextFrame();
    updateView();
}else{
    //You're at the last page of the quiz
}

}

function updateView():void
{
question.text = “There are some signs that there is potential conflict here what do you think is the underlying cause?”;
}

function getAnswer():void
{
option1.selected == true;
}

I’ve added a jpg of what the quiz looks like. Thank you.