Flex 3 Using an image as a border

I am working on an custom cont开发者_StackOverflow社区ainer and I need a border for this container. I have a 15x15 image that I am creating a 9-slice border skin with. The issue that I am having is that the border skin does not appear the way that I had hoped it would.

Here is a ss of the skin in place.

Ideally I should have a transparent box with a 5 pixel border around it.

Here is my current testing code:

CSS Code:

Box
 {
borderSkin: Embed(source="15x15.png",
            scaleGridLeft="5",
            scaleGridTop="5",
            scaleGridRight="10",
            scaleGridBottom="10");
 }

MXML Code:

<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
<mx:Style source="MainTest.css"/>

<mx:Box id="tw" width="400" height="400">

</mx:Box>
</mx:WindowedApplication>

Try this :

Box{
    background-image: Embed("15x15.png",
       scaleGridTop="5", 
                   scaleGridBottom="10", 
                   scaleGridLeft="5", 
                   scaleGridRight="10");

    background-size:"100%";
}