Facebook external eval ?

Hi, I have a unity web game which uses a external .js plugin which I source in the unity html ...But facebook uses the .unity3d file directly and I am not able to source in the .js plugin or the html file...on the facebook developer page they say...


Injecting your own HTML/JS

You may wish to add HTML or Javascript code around the Unity object. You can do this using Unity Web Player's DOM mutation/JS execution functions, such as Application.ExternalEval().

Example

Add a div element to the top of the iframe containing the game, which might contain a header for cross-promotion or related uses.

string injection =
"var headerElement = document.createElement('div');" +
"headerElement.textContent = ('Check out our other great games: ...');" +
"var body = document.getElementsByTagName("body")[0];" +
"var insertionPoint = body.children[0]; " +
"body.insertBefore(headerElement, insertionPoint);";
Application.ExternalEval(injection);

..I dont know how to or where to put in the code to get it work...here is what i put in the unity html file to reference the .js plugin...
</script>
<script type="text/javascript" src="JAVAPLUGIN.js">
</script>

Can you tell me how we can achieve this...reference the html and js plugin ?
Please Help !