function LessonChange(){
			if (document.getElementById('os0').selectedIndex==1 || document.getElementById('os0').selectedIndex==2)
				document.getElementById('lessonpeople').style.display="block";
			else
				document.getElementById('lessonpeople').style.display="none";
		}
		function ValidateLesson(){
			if (document.getElementById('os0').selectedIndex<1) {
				alert("Please select a lesson")
				return false;
			}
			else
				return true;
		}