SWFObject not working on IE6, Player F9, winXP SP2!

[asscripter]

I am using SWFObject to embed an swf into the html page. Now this page is working perfect on my computer. Means - I am able to see the swf when I launch the html.

But my client is not able to see the swf when he launches the html. He get a javascript error as:

"flashMovie" is null or not an object.

my code in the html:
var flashMovie; // get our flash movie object
function init() {
if (document.getElementById) {
flashMovie = document.getElementById("my_swf");
}
}

var fo = new SWFObject("myfile.swf", "my_swf", "400", "373", "9.0.115,0", "#000000", true);

My client has the machine specs as
Win XP SP2
Flash player 9
IE 6

Can you please tell me why the swf is not showing. What can i do to correct this?

thanks.