Ordering Table Columns

Hello all,

Totally new to this and I'm just doing a frequency distribution analysis
on T-shirt sales by size.  I have a .csv with 60 orders.  I read in the
data using read.csv.  If I look at the summary() or table() of the data it
looks fine, except that the shirt sizes are alphabetical rather than from
S-XXL--so the bar graph loses the shape of the data based on size.

All I want to do is get the table to arrange the data:
S M L XL XXL

Here's the code that I've run that got me closer to what I want.  It seems
like it should be simple, but going through the "R in a Nutshell" and
asking Google as many different ways as I can think to phrase it are
turning up nothing.

shirt <- read.csv("http://localhost/examples/tshirt_purchases.csv",
header=TRUE, sep = ",", nrows=60)
shirt.table<-summary(shirt)
shirt.table

 Shirt.Size
 L  :20    
 M  :20    
 S  :11    
 XL : 7    
 XXL: 2  

What I want is:

Shirt.Size    
S  :11   
M  :20 
L  :20  
 XL : 7    
 XXL: 2  

Does anyone know how to do this, or am I coming at it from the wrong
direction?
If this has been answered previously and I've just failed to find it in my
searches, please accept my apologies.  

Many Thanks,
Chris