Alpha setInterval problem

I’ve got this code on frame one together with three txt fields. Everything works fine where each txt appear after 5 sec interval (lovely…). But when I add a background or anyhting else for that matter, nothings happens…no fading in…

Does anyone know why?
here’s my code:


txtField._alpha = 0
txtField1._alpha = 0
txtField2._alpha = 0
_root.currentTextField = txtField;
_root.counter = 0;
function alphaIt()
{
		
		_root.currentTextField._alpha+=5;
		if( _root.currentTextField._alpha>=100)
		{
				_root.counter++;
				if(_root.counter < 3)
				{
					    
					 _root.currentTextField = _root["txtField"+_root.counter]
				}
				else
				{
					 trace("intervall cleared")
					 clearInterval(_global.intervalId)
				}
		}
}
_global.intervalId = setInterval(alphaIt,100);

Appreciate any help! :esmirk: