Not performing calculation

programming flash
1

So i think i have fully coded my calculator but it still doesn’t seem to be performing the calculations correctly. I can’t see where i am going wrong. If i perform a calculation let’s say 6*2 it outputs NaN then i straight away + by let’s say 5 it outputs NaN again. And it doesn’t make the operators display only once, so if i click on ‘+’ twice it will display twice in the display when it is meant to only display once and in one of my functions i cleared the display field so that it would replace the number’s when the next operation is performed but it doesn’t seem to be doing that. I have been going over the code several times but i can’t seem to identify where the problem is coming from.

import flash.events.MouseEvent;
 
var btn:Array = new Array();
for(var i = 0; i < 10; i++) {
                var myBtn:Btn = new Btn();
                myBtn.buttonMode = true;
                myBtn.mouseChildren = false;
                myBtn.num = Number(i);
                myBtn.caption.text = String (i);
                addChild(myBtn);
                btn.push(myBtn);
                btn*.addEventListener(MouseEvent.CLICK,pressNumber);//EVENT TO ADD NUMBERS TO DISPLAY                                      
}
 
//OPERATORS//
var operate:Array=new Array("÷","x","-","+");
var operators:Array = new Array();
for(var io:int = 0; io < 4; io++) {
                var opBtn:Btn_operator = new Btn_operator();
                opBtn.buttonMode = true;
                opBtn.mouseChildren = false;
                opBtn.op = Number(operators);
                addChild(opBtn);
                operators.push(opBtn);               
                opBtn.addEventListener(MouseEvent.CLICK, pressOperator);//EVENT TO ADD OPERATORS TO DISPLAY
}
 
//EQUALS
var equals:Btn_equals = new Btn_equals();
                equals.buttonMode = true;
                equals.mouseChildren = false;
                equals.caption_op.text = String ("=");
                addChild(equals);
               
equals.addEventListener(MouseEvent.CLICK, performEquals);//EVENT TO CALCULATE
 
 
//VARIABLE HANDLE OPERATION NOT BUTTON
var operates:String;
 
//HANDLE FIRST AND SECOND VALUE
var num1:Number;
var num2:Number;
 
var currentNumber:String ="";
function pressNumber(e:MouseEvent):void{
                       display_txt.appendText(e.target.num);
                                   currentNumber+=(e.target.num);
                                   trace(e.target.num);
}
 
function setNumber():void{
                if (isNaN(num1)){
             num1 = Number(currentNumber);
             }
             else
                                                 {
               num2 = Number(currentNumber);
             }
             currentNumber = "";
             }
 
//DISPLAY OPERATORS
function pressOperator(event:MouseEvent):void{         
               
                operates = operate[operators.indexOf(event.target)];
                display_txt.appendText(operate[operators.indexOf(event.target)]);
                trace(operate[operators.indexOf(event.target)]);
                setNumber();
                //trace(operates);
                //CHECKING FOR VALUES AND STORING NUMBERS        
                if(!(isNaN(num1)) || (isNaN(num2))){
                                performCalculation();
                }
}
function performCalculation():void{
               
                switch (operate){
                case "/":
                                num1/=num2;
                break;
                case "x":
                                num1*=num2;
                break;
                case "-":
                                num1-=num2;
                break;
                case "+":
                                num1+=num2;
                break;
                                default:
                break;
}
               
}
 
function performEquals(e:MouseEvent):void{
                //display_txt.text=String(num1);
                num2=NaN;
                performCalculation();
                answer_txt.text=String(num2);
 
                                trace(num2);
               
                }

I have not added the full code as it is too long, i have just added the parts which relate to each other. Help would be greatly appreciatted, thank you. I have seen NaN so many times it is becoming my enemy.