Aggressively searches for TextFields, and attaches an event listener.

findFields.as

/**
 * Note - you'll need:
 *   import flash.events.FocusEvent
 * 
 * Also, try/catch is pretty expensive processing-wise.  Avoid it.
 * I threw it together that way so you can play with it and get some
 * better reporting on what's going on without it bombing on you.
 * Once you refine it to search without throwing any exceptions on
 * missing properties or methods, kill the try/catch.
 */

function saveField(e:FocusEvent):void {
	var fieldName:String = e.target.name;
	var fieldValue:String = e.target.text;
	
	// Save
}

function findFields(rootContainer:DisplayObjectContainer):void {
	for(var i=0; i < rootContainer.numChildren; i++) {
		var item:* = rootContainer.getChildAt(i);
		try { // Let's see if we have a textfield
			if (item.getQualifiedClassName() == "flash.text.TextFormat") {
				item.addEventListener(FocusEvent.FOCUS_OUT, saveField)
			}
			else { // Nope - let's try to keep digging
				findFields(item);
			}
		} catch (e:Error) {
			trace(e.toString());
		}
	}
}

findFields(root);