Basic Question: How to call a Class in mxml and Run it

Question

Hi.  I'm doing my bit to try and learn Away3D.  I have successfully run the application from Flash Builder 4.0 standard as an ActionScript Project.  However now I want to run it as a Flex Project which gives me the ability to run it as a desktop application via AIR.
I have the following code:  (Why is my code not executing the SphereDemo.as Class which is supposed to be able to display a Poly Sphere on the viewport?)
<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
                       xmlns:s="library://ns.adobe.com/flex/spark"
                       xmlns:mx="library://ns.adobe.com/flex/mx"
                       creationComplete="runMe();">
    <fx:Declarations>
        <!-- Place non-visual elements (e.g., services, value objects) here -->
    </fx:Declarations>
    <fx:Script>
        <![CDATA[
            public function runMe():void
                var mySphere:SphereDemo = new SphereDemo();
                mySphere;
                //SphereDemo;
        ]]>
    </fx:Script>
</s:WindowedApplication>

Answer 1

Here is the complete error message:
TypeError: Error #1009: Cannot access a property or method of a null object reference.
    at AwayAS/initEngine()[C:\Users\root\Adobe Flash Builder 4.6\AwayMXML\src\AwayAS.as:27]
    at AwayAS()[C:\Users\root\Adobe Flash Builder 4.6\AwayMXML\src\AwayAS.as:17]
    at SphereDemo()[C:\Users\root\Adobe Flash Builder 4.6\AwayMXML\src\SphereDemo.as:8]
    at AwayMXML()[C:\Users\root\Adobe Flash Builder 4.6\AwayMXML\src\AwayMXML.mxml:12]
    at _AwayMXML_mx_managers_SystemManager/create()[_AwayMXML_mx_managers_SystemManager.as:51]
    at mx.managers.systemClasses::ChildManager/initializeTopLevelWindow()[E:\dev\4.y\frameworks\ projects\framework\src\mx\managers\systemClasses\ChildManager.as:311]
    at mx.managers::SystemManager/initializeTopLevelWindow()[E:\dev\4.y\frameworks\projects\fram ework\src\mx\managers\SystemManager.as:3057]
    at mx.managers::SystemManager/http://www.adobe.com/2006/flex/mx/internal::kickOff()[E:\dev\4.y\frameworks\projects\framework\src\mx\managers\SystemManager.as:2843]
    at mx.managers::SystemManager/http://www.adobe.com/2006/flex/mx/internal::preloader_completeHandler()[E:\dev\4.y\frameworks\projects\framework\src\mx\managers\SystemManager.as:2723]
    at flash.events::EventDispatcher/dispatchEventFunction()
    at flash.events::EventDispatcher/dispatchEvent()
    at mx.preloaders::Preloader/timerHandler()[E:\dev\4.y\frameworks\projects\framework\src\mx\p reloaders\Preloader.as:542]
    at flash.utils::Timer/_timerDispatch()
    at flash.utils::Timer/tick()