Some time we need to apply the full screen in swf. The following code can be used for full screen.

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
               xmlns:s="library://ns.adobe.com/flex/spark" 
               xmlns:mx="library://ns.adobe.com/flex/mx" applicationComplete="init(event)">
    <fx:Declarations>
        <!-- Place non-visual elements (e.g., services, value objects) here -->
        <fx:String id="dispState" />
    </fx:Declarations>

    <fx:Script>
        <![CDATA[
            import flash.display.StageDisplayState;

            import mx.core.FlexGlobals;
            private function init(evt:Event):void {
                /* Set up full screen handler. */

                FlexGlobals.topLevelApplication.stage.addEventListener(FullScreenEvent.FULL&#95;SCREEN, fullScreenHandler);
                dispState = FlexGlobals.topLevelApplication.stage.displayState;
            }

            private function fullScreenHandler(evt:FullScreenEvent):void {
                dispState = FlexGlobals.topLevelApplication.stage.displayState + " (fullScreen=" + evt.fullScreen.toString() + ")";
                if (evt.fullScreen) {
                    /* Do something specific here if we switched to full screen mode. */
                } else {
                    /* Do something specific here if we switched to normal mode. */
                }
            }

            private function toggleScreen():void {
                try {
                    switch (FlexGlobals.topLevelApplication.stage.displayState) {
                        case StageDisplayState.FULL&#95;SCREEN:
                            /* If already in full screen mode, switch to normal mode. */
                            FlexGlobals.topLevelApplication.stage.displayState = StageDisplayState.NORMAL;
                            break;
                        default:
                            /* If not in full screen mode, switch to full screen mode. */
                            FlexGlobals.topLevelApplication.stage.displayState = StageDisplayState.FULL&#95;SCREEN;
                            break;
                    }
                } catch (err:SecurityError) {
                    // ignore
                }
            }
        ]]>
    </fx:Script>


    <mx:Label x="10" y="20" text="width={FlexGlobals.topLevelApplication.width}" />
    <mx:Label x="10" y="50" text="height={FlexGlobals.topLevelApplication.height}" />
    <mx:Label text="displayState={dispState}" />

    <mx:Button x="10" y="100" label="FullScreen" click="toggleScreen()" />
</s:Application>

In above code the toggleScreen function will handel the full screen feature.