Cant use FX declaration in flex application - actionscript-3

Question

Since Im really new at this I will try to explain my problem as good as I can.
I have created an rss feed in flex. Since i dont really know the differens between s / mx / fx I cant figure out what the problem is. Any how. My rss feed application works fine. In the beginning of the application i have this code
<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600">
As you can se the application starts with an s:application.
Under this i have the declaration tags
<fx:Declarations>
<mx:HTTPService id="RSSFeed" result="RSSFeed_resultHandler(event)" fault="RSSFeed_faultHandler(event)"/>
</fx:Declarations>
The problem is that I want to import this RSS feed application on another application that I created.
Thats one starts with mx:application
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
layout="vertical"
verticalAlign="top"
backgroundColor="black"
creationComplete="init();" viewSourceURL="srcview/index.html" xmlns:s="library://ns.adobe.com/flex/spark">
Now the problem is that when i want to write the HTTP service inside the declaration types. IT wont work since the declaration tags aren't available here.
I tryied to write it witout the declaration type but get the error message
Multiple markers at this line:
-1180: Call to a possibly undefined method RSSFeed_faultHandler.
-Line breakpoint: main.mxml [line: 11]
-1180: Call to a possibly undefined method RSSFeed_resultHandler.
Any ideas ?