Looking for a way to anchor a background image

[Abs0lute]

Hello all,
I have a website in the works, and we're really liking the way the design is heading. However, I've got a small issue. The site is for a company that builds Radio and TV towers. Using their logo (a tower) at the top, I want to place a background image in the body that's like a signal radiating out (concentric circles). I've got that done, and it looks nice, but only at a certain window size. The logo is contained in a wrapper that has it's margins set to 0 auto. The background image is positioned with %. But if you resize the window, the center of the circles do not stay with the tower in the logo.
Does anyone have any ideas on how I can keep the circles always aligned with the tower logo, no matter the browers window size?
You can see an example here:
http://www.cycletower.com/BETA/index.html
Thanks in advance for your help!
Abs0lute

[davelf]

body {
	width:auto;
	background-image:url(#);
	background-repeat:no-repeat;
	background-position:bottom center;
	margin:0 auto;
	left:auto;
	top:auto;
}

you can add that code in your css style, that code will help you to keep the background and all component stay in the middle of your browser, even you resize your browser.