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;
}