char and key code checker

/**
 * Copyright tjoen ( http://wonderfl.net/user/tjoen )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/9VMo
 */

<?xml version="1.0"?>
<!-- charts/ShowCharAndKeyCodes.mxml -->
<s:Application 
    xmlns:fx="http://ns.adobe.com/mxml/2009"    
    xmlns:mx="library://ns.adobe.com/flex/mx"     
    xmlns:s="library://ns.adobe.com/flex/spark"
    creationComplete="init()"
    width="650">

    <s:layout> 
        <s:VerticalLayout/> 
    </s:layout>

  <fx:Script><![CDATA[
     import flash.events.KeyboardEvent;

     private function init():void {
        ti1.setFocus();
        this.addEventListener(KeyboardEvent.KEY_DOWN, trapKeys);
     }
            
     private function trapKeys(e:KeyboardEvent):void {
        ta1.text = String(e.toString());
        
        l1.text = numToChar(e.charCode) + " (" + String(e.charCode) + ")";
        l2.text = numToChar(e.keyCode) + " (" + String(e.keyCode) + ")";
     }
    
    private function numToChar(num:int):String {
        if (num > 47 && num < 58) {
            var strNums:String = "0123456789";
            return strNums.charAt(num - 48);
        } else if (num > 64 && num < 91) {
            var strCaps:String = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
            return strCaps.charAt(num - 65);
        } else if (num > 96 && num < 123) {
            var strLow:String = "abcdefghijklmnopqrstuvwxyz";
            return strLow.charAt(num - 97);
        } else {
            return num.toString();
        }
    }        
  ]]></fx:Script>

  <s:TextInput width="50%" id="ti1"/>
  
  <s:Panel id="mainPanel" width="100%" height="100%">
     <mx:Form>
        <mx:FormItem label="Char (Code)">
           <mx:Label id="l1"/>
        </mx:FormItem>
        <mx:FormItem label="Key (Code)">
           <mx:Label id="l2"/>
        </mx:FormItem>
        <mx:FormItem label="Key Event">
           <mx:TextArea id="ta1" width="250" height="200" editable="false"/>
        </mx:FormItem>
     </mx:Form>
  </s:Panel>      
                
</s:Application>