function fset() {
	if (window.innerHeight && window.scrollMaxY) {
		var dis = document.getElementById('content').offsetHeight + document.getElementById('content').offsetTop + 10;
		if( dis <= 800 ) { dis = 800; }
		document.getElementById('logo').style.height = dis + 'px';
	} else {
		document.getElementById('logo').style.height = '800px';
	}
}