I have the following table, how to make it in ascending order with All option.

I have a table mstquarters where this kind of data is there with fields quarter and level
quarter                          level
Sep - Dec 2010 - P1         1
Jan - Mar 2011 - P2              2
Apr - Jun 2011 - P3              3
Jul - Sep 2011 - P4              4
Oct - Dec 2011 - P5              5
Jan - Mar 2012 - P6              6
Apr - Jun 2012 - P7              7
Jul - Sep 2012 - P8              8

I want the output should come as
All
Sep - Dec 2010 - P1  
Jan - Mar 2011 - P2
Apr - Jun 2011 - P3
Jul - Sep 2011 - P4
Oct - Dec 2011 - P5
Jan - Mar 2012 - P6
Apr - Jun 2012 - P7
Jul - Sep 2012 - P8
i.e ALL, P1, P2, P3... etc
This query is not working

select quarter from(select 'All Quarters' as quarter from mstquarters union select distinct quarter from mstquarters)x order by 1