user: Question: What is the Tie no of the Port Vale Away game?
Columns: ['Tie no', 'Home team', 'Score', 'Away team', 'Date']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['1', 'Enfield', '0–0', 'Harwich & Parkeston', '20 November 1976']
SQL:

assistant: SELECT "Tie no" FROM "Table" WHERE "Away team" = 'Port Vale';