Build file doesn't include image files in Assets

I draw buttons with GUI apis of Javscript like this

 function OnGUI(){
     if(GUI.Button(new Rect(10,10,100,100),Resources.LoadAssetAtPath("Assets/images/circle.png", Texture2D))){
         // bra bra bra
     }
 }

This script works well on Game view when play button is clicked on Unity Editor.

But images are not shown with built application.

I build apps for PC,Mac,Flash but all of them don't show any images.

build files looks have no image files inside.

Please tell me how to import imagefile with build files.

This is the project file: https://dl.dropbox.com/u/281264/unity/GuiTest1.zip

Thank you.