domOK = Boolean(document.getElementById);
// domOK = false;

function getWidth(element) {
	var x;
	return ((x=element.style.pixelWidth) || (x=element.clientWidth) || (x=element.offsetWidth) || (x=parseInt(element.style.width))) ? x : null;
}

function setOffset () {
	if (domOK) {
		offsetLeft = 0;
		var w = (getWidth(document.documentElement));
		if (w>800) offsetLeft=Math.round((w-780)/2);
	}
}

function resize() {
	if (domOK) {
		setOffset();
		document.getElementById("main").style.left = offsetLeft + "px";
	}
}

if (domOK) {
	window.onresize = resize;
	window.onload = resize;
	setOffset();
	document.write('<style type="text/css">');
	document.write('#main {left:' + offsetLeft + 'px}');
	document.write('</style>');
}