How about:

Select max(year_monthname) from mytable where month_closed = true
>Hi,
>
>I have a table shows 12 month and the status of each month if it's closed of not, how to find the last month closed in a SQL Staement, the file looks like this:-
>
>year 1 2 3 4 5 6 7 8 9 10 11 12
>2007 T T T T T T T T F F F F
>
>
>the field name are not numbers its just for the example