public void init(){
			var db = database;
			db.CreateTable<employee>();

			var e1 = new employee () {
				Name = "Liu",
				AvailableTime = "30 mins",
				Position = "QUT"

			};

			db.Insert (e1);
			
	


		}
	public int InsertOrUpdateNote(employee employee){
			return database.Table<employee> ().Where (x => x.Name == employee.Name).Count () > 0 
				? database.Update (employee) : database.Insert (employee);
		}