It really depends on when you want to update the dynamic text field, with the text field input data.
, :
myDynamicTF.text = myInputFT.text;
myDynamicTF._text = myInputFT._text;
, , AS3 TextField Change event
myInputFT.addEventListener(Event.CHANGE, changeHandler);
private function changeHandler(e:Event):void
{
myDynamicTF.text = myInputFT.text;
}
AS2 :
myInputFT.onChanged = function(textfield_txt:TextField)
{
myDynamicTF._text = textfield_txt._text;
};