Proportional Full screen background

Hi everyone…I am new to the Kirupa forum…and I’m not sure if I am posting this to the correct forum
:sure:
http://anita.mamigon.com/
I got do display the image full background (using the swfObject and it’s html utility) but it is somehow “stretched” and looks kind of “unnatural”.
I haven’t used any Actionscript in my fla…simply javascript in the main html document

My actual image size is 850 x 638 px.

Is there a way to fill out the background proportionally without stretching the actual image ?

Anyone has any ideas on how to achieve this?

Thanks
Patty