public String execute()throws Exception{
		con = getConnection();
		try{
			String sql = "select * from Author";
			st = (Statement)con.createStatement();
			ResultSet res = st.executeQuery(sql);
			boolean flag = false;
			String TeAuthorID = null;
			
			while(res.next()){
				if(Authorname.equals(res.getString("Name"))){
					TeAuthorID=new String(res.getString("AuthorID"));
					flag = true;
					break;
				}
			}
			if(flag){
				String sq2 = "select * from Book";
				res = st.executeQuery(sq2);
				while(res.next())
					if(TeAuthorID.equals(res.getString("AuthorID")))
						BookList.add(new String(res.getString("Title")));
				con.close();
				return "Success";
			}	
			else{ 
				con.close();
				return "Failed";
			}
		}catch(Exception e){
			System.out.println("Errors."+e.getMessage());
			return "Else";
		}
	}