user: Question: What is the Surface of the Tournament on June 11, 2006?
Columns: ['Date', 'Tournament', 'Surface', 'Opponent in final', 'Score', 'Prize Money']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['March 27, 2005', 'Athens', 'Clay', 'Mădălina Gojnea', '6-1 6-3', '$10,000']
SQL:

assistant: SELECT "Surface" FROM "Table" WHERE "Date" = 'June 11, 2006';