Operator Display AS3

For the calculator i am creating i have so far got all d buttons inputting into the display area such as the numbers and the operators. However for the operators when i try to store the value into two number variables ‘num1’ and ‘num2’, i traced them to test if they were working fine however they output as ‘NaN’. here is the code i have so far and the highlighted area is what i am working on currently


import flash.events.MouseEvent;var btn:Array = new Array();for(var i = 0; i < 10; i++) {          var myBtn:Btn = new Btn();          myBtn.y = 15;          myBtn.x = i * 100 + 15;          myBtn.width = 48;          myBtn.height = 48;          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  }btn[0].y += 370;btn[0].x += 10; btn[1].y += 310;btn[1].x += -90;btn[2].y += 310;btn[2].x += -130;btn[3].y += 310;btn[3].x += -170;btn[4].y += 250;btn[4].x += -390;btn[5].y += 250;btn[5].x += -430;btn[6].y += 250;btn[6].x += -470;btn[7].y += 190;btn[7].x += -690;btn[8].y += 190;btn[8].x += -730;btn[9].y += 190;btn[9].x += -770;//OPERATORS//var operators:Array = new Array();for(var io:int = 0; io < 6; io++) {          var opBtn:Btn_operator = new Btn_operator();          opBtn.width = 48;          opBtn.height = 48;          opBtn.buttonMode = true;          opBtn.mouseChildren = false;          opBtn.caption_op.text = String (".");          addChild(opBtn);          operators.push(opBtn);           operators[io].addEventListener(MouseEvent.CLICK, pressOperator);//EVENT TO ADD OPERATORS TO DISPLAY}//ADD DOTvar dot:Btn_dot = new Btn_dot();          dot.width = 48;          dot.height = 48;          dot.buttonMode = true;          dot.mouseChildren = false;          dot.caption_op.text = String (".");          addChild(dot);dot.y += 383;dot.x += 78;dot.addEventListener(MouseEvent.CLICK, addDot);//EVENT TO ADD DOT TO DISPLAY//BACKSPACEvar goBack:Btn_backspace = new Btn_backspace();          goBack.width = 48;          goBack.height = 48;          goBack.buttonMode = true;          goBack.mouseChildren = false;          goBack.caption_op.text = String ("<--");          addChild(goBack);goBack.y += 203;goBack.x += 256;goBack.addEventListener(MouseEvent.CLICK, backSpace);//EVENT TO GO BACK SPACE IN DISPLAY//BACKSPACEvar clearAll:Btn_clear = new Btn_clear();          clearAll.width = 48;          clearAll.height = 48;          clearAll.buttonMode = true;          clearAll.mouseChildren = false;          clearAll.caption_op.text = String ("C");          addChild(clearAll);clearAll.y += 323;clearAll.x += 256;clearAll.addEventListener(MouseEvent.CLICK, clearFields);//EVENT TO GO BACK SPACE IN DISPLAYoperators[0].y += 383;operators[0].x += 138;operators[0].caption_op.text = String("=");operators[1].y += 383;operators[1].x += 198;operators[1].caption_op.text = String("/");operators[2].y += 323;operators[2].x += 198;operators[2].caption_op.text = String("*");operators[3].y += 263;operators[3].x += 198;operators[3].caption_op.text = String("-");operators[4].y += 203;operators[4].x += 198;operators[4].caption_op.text = String("+");operators[5].y += 263;operators[5].x += 256;operators[5].caption_op.text = String("-/+");//VARIABLE HANDLE OPERATION NOT BUTTONvar operate:String;//HANDLE FIRST AND SECOND VALUEvar num1:Number;var num2:Number;//grouping all buttons in function//display_txt.text = "0";//DISPLAYING NUMBERS IN DISPLAY//var numberEntered:String ="";function pressNumber(e:MouseEvent):void{                 display_txt.appendText(e.target.num);}//DISPLAY OPERATORSfunction pressOperator(event:MouseEvent):void{          var operatorEntered:String;          display_txt.appendText(event.currentTarget.caption_op.text);          //CHECKING FOR VALUES AND STORING NUMBERS          if(!num1){                    //CONVERT STRING TO NUMBER                    num1=Number(display_txt.text);                    operate = operatorEntered;                    display_txt.text = "";                    trace(num1);          }          else if(!num2){                    num2 = Number(display_txt.text);                    operate = operatorEntered;          }          }//CLEARS DISPLAY AREAfunction clearFields(event:MouseEvent):void{          display_txt.text = "";          num1=NaN;          num2=NaN;          }//ADDS DECIMAL PLACEfunction addDot(event:MouseEvent):void{          if (display_txt.text.indexOf(".")==-1){                    display_txt.appendText(".");          }          }

I need to see if the number is stored when i click on d operator. In the trace It is meant to display the number entered after i click on a operator but it displays as ‘NaN’ I am guessing all of that function has mistakes. it is function pressOperator i am working with