user: Question: Visitor of Dallas, and a Date of June 12 had what highest attendance?
Columns: ['Date', 'Visitor', 'Score', 'Home', 'Decision', 'Attendance']
Types: ['text', 'text', 'text', 'text', 'text', 'real']
Sample row: ['June 8', 'Buffalo', '3–2 OT', 'Dallas', 'Belfour', 17001.0]
SQL:

assistant: SELECT MAX("Attendance") FROM "Table" WHERE "Visitor" = 'Dallas' AND "Date" = 'June 12';