// =========================
function getWindowHeight() {
	var windowHeight = 0;
	if (typeof(window.innerHeight) == 'number') {
		windowHeight = window.innerHeight;
	} else {
		if (document.documentElement && document.documentElement.clientHeight) {
			windowHeight = document.documentElement.clientHeight;
		} else if (document.body && document.body.clientHeight) {
			windowHeight = document.body.clientHeight;
		}
	}
	return windowHeight;
}
// =========================
function setPage() {
	if (document.getElementById) {
		var windowHeight = getWindowHeight();
		if (windowHeight > 0) {
			var contentHeight = document.getElementById('centerBox').offsetHeight;
			if (windowHeight - contentHeight >= 0) {
				document.getElementById('centerBox').style.height =  windowHeight + 'px';
			} else {
				document.getElementById('centerBox').style.height = 'auto';
			}
		}
	}
}
// =========================
window.onresize = function() {
	setPage();
}