Calculator not working

[FONT=Verdana][SIZE=2][COLOR=Black]I’m in a Web Design class and atm, I’m working on chapter 8 of Flash CS5 case problem.

I have to make a calculator. Can I just say that AS3 makes me frusterated? D:

Anyway, after I finished what the book told me to do whilst getting confused in some areas, I got many compiler errors. I managed to get rid of them but in the end, my calculator isn’t working, haha.

Here’s the whole code:

import flash.events.MouseEvent;
calcTotal_btn.addEventListener(MouseEvent.CLICK, calculateTourCost);
function calculateTourCost(event:MouseEvent):void {

var totalCost:Number;
var base_cost:Number;
var people:Number = int(numberOfPeople.text);
var cost_per_person:Number;
if (people < 8)
{
    cost_per_person = 10;
}
if (people < 7 > 16)
{
    cost_per_person = 8;
}
if (people < 15)
{
    cost_per_person = 5;
}

//Use the switch statement to assign the tour's base cost
switch (tourType_txt.text)
{
    case "A" :
    case "a" :
        base_cost = 20;
        break;
    case "B" :
    case "b" :
        base_cost = 25;
        break;
    case "C" :
    case "c" :
        base_cost = 30;
        break;
    default :
        base_cost = 40;
}

//Determines total cost
people = int(numberOfPeople) + int(base_cost);
totalCost = people * cost_per_person;
totalCost = (totalCost);

}

If anyone can help me out, I’d greatly appreciate it.
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