Flex bind variable has no effect - actionscript-3

Question

No matter what I do, I cannot have any effect on Flex MXML elements during initialization.
I want to display a different logo depending on whether a flashVar is true or not.
For some reason the flashvar has no effect on how the elements appear.
Am I missing anything ?
<?xml version="1.0" encoding="utf-8"?>
<s:Group xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:components="ru.kutu.grindplayer.views.components.*"
mouseEnabled="false"
implements="ru.kutu.grind.views.api.IMainView"
preinitialize="preinitialize(event)"
>
<s:states>
<s:State name="initializing" />
<s:State name="ready" />
<s:State name="error" />
</s:states>
<s:BorderContainer
id="logoContainer"
left="0" right="0"
top="0" bottom="0"
mouseEnabled="false"
includeIn="initializing"
backgroundColor="0x070707"
borderVisible = "false"
>
<s:Image
id="logoPaid"
verticalCenter="0"
horizontalCenter="0"
source="#Embed('/../assets/skin/dark.png')"
visible="{is_paid}"
/>
<s:Image
id="logoFree"
verticalCenter="0"
horizontalCenter="0"
source="#Embed('/../assets/skin/dark_free.png')"
visible="{!is_paid}"
/>
</s:BorderContainer>
<components:PlayerView
id="playerView"
left="0" right="0"
top="0" bottom="0"
visible="false"
visible.ready="true"
/>
<s:Label
id="errorDisplay"
width="80%"
mouseEnabled="false"
verticalCenter="0"
horizontalCenter="0"
includeIn="error"
itemCreationPolicy="immediate"
/>
<s:transitions>
<s:Transition
fromState="*" toState="*"
autoReverse="true"
interruptionBehavior="stop"
>
<s:Fade
target="{this}"
duration="300"
/>
</s:Transition>
</s:transitions>
<fx:Script>
<![CDATA[
import mx.core.FlexGlobals;
import mx.events.FlexEvent;
[Bindable]
private var is_paid:Boolean;
public function set errorText(value:String):void {
errorDisplay.text = value;
}
public function initializing(is_paid:Boolean):void {
currentState = "initializing";
}
public function ready():void {
currentState = "ready";
}
public function error():void {
currentState = "error";
}
private function preinitialize(event:FlexEvent):void {
is_paid = FlexGlobals.topLevelApplication.parameters.is_paid;
}
]]>
</fx:Script>

Answer 1

I think you parse String into Boolean. Cause params names and values are String, try this instead:
is_paid = FlexGlobals.topLevelApplication.parameters.is_paid == 'true';