function changeDisplay(onid, ontab) {
	var onID = document.getElementById(onid);
	var onTab = document.getElementById(ontab);
	for (i = 1; i < 5; i++) {
		key = 't' + i;
		if (document.getElementById(key) != null) {
			document.getElementById(key).style.display = 'none';
		}
		key = 'u' + i;
		if (document.getElementById(key) != null) {
			document.getElementById(key).className = 'mss-tab';
		}

	}

	if (onID) onID.style.display = 'block';
	if (onTab) onTab.className= 'mss-tab-on';

}
changeDisplay('t1', 'u1');