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 setContent() {

if (document.getElementById) {

var windowHeight = getWindowHeight();

if (windowHeight > 0) {

var contentElement = document.getElementById('container'); // Be sure to specify the correct ID

var contentHeight = contentElement.offsetHeight;

if (windowHeight - contentHeight > 0) {

contentElement.style.position = 'relative';

contentElement.style.top = ((windowHeight / 2) - (contentHeight / 2)) + 'px';

}

else {
contentElement.style.position = 'static';
}
}

}

}