[flexcoders] Referencing components from custom controls

[nocturnal_world]

Hello,

I'm a noob in flex. I have no training on it but I try to learn it as 
much as I could.

I think my problem is simple to you guys.

I have this in my main.mxml code

<mx:Image x="204" y="7" source="images/new.gif" visible="false" 
id="imgNewMessage"/>

Now, if I reference it in an action script file like so...

imgNewMessage.visible=false;

it works fine.

But if I try to do that in a custom control, like this

package mycontrol.containers
{
import mx.controls.Alert;
import flash.display.DisplayObject;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.events.TimerEvent;
import flash.utils.Timer; 
.
.
.
public function doSomething():void {
imgNewMessage.visible=false;
}

}


I'm getting an error. Its like it does'nt know imgNewMessage.

How can I reference it? I thought components are accessible globally.

Hope you guys can help.

Thanks in advance.