Using two different tables in query
                            
                         
                        
                     
                 
                
                    In my ASP.NET application, I am wishing to select top 20 records (10 and 10) from two different tables named 'PostedByAdmins' and 'PostedByGuest'. I have used following queries but no use:-
SELECT TOP 20 [title], [source], [description] FROM [PostedByAdmins, PostedByGuest] ORDER BY [id] DESC
SELECT TOP 20 [title], [source], [description] FROM [PostedByAdmins], [PostedByGuest] ORDER BY [id] DESC
Even I tried to delete TOP 20 even I don't wish this but no use like
SELECT [title], [source], [description] FROM [PostedByAdmins], [PostedByGuest] ORDER BY [id] DESC
I tried to delete TOP 20 and ORDER by but no use as
SELECT [title], [source], [description] FROM [PostedByAdmins], [PostedByGuest]
For the demonstration purpose I check both table one by one and this worked fine
SELECT TOP 20 [title], [source], [description] FROM [PostedByAdmins] ORDER BY [id] DESC
SELECT TOP 20 [title], [source], [description] FROM [PostedByGuest] ORDER BY [id] DESC
So, there is no problem with development of tables or say in other coding except query. 
So, guys what query I use to fix my issue. Remeber I need top 10 records from both tables. 
Thanks in advance.