ActionScript 3.0 :: Global Var Returns Null In TextField

I have a small issue, which is important for my project though. Namely my global var returns null when I need it. I have a global var class:
Code:
package {
public class Global {
public static var premiseGlobalName:String = new String();
}}

In another class I'm setting this var like so:
Code:
public function onButtonRollOver (event:MouseEvent):void {
Global.premiseGlobalName = "My home";
this.addChild(premiseMenu);
}

The second line in the method calls another class to the stage which uses the global var. I trace the global var:
Code:
public function initPremiseMenu():void {
trace("GLOBAL: " + Global.premiseGlobalName);
}
But it returns an empty value.

I want to use the global var in a textfield like so:
Code:
premiseTip.text = Global.premiseGlobalName;