user: Question: What was the tie number for the game with an away team of Hartlepool United?
Columns: ['Tie no', 'Home team', 'Score', 'Away team', 'Date']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['1', 'Watford', '2–1', 'Derby County', '28 January 1989']
SQL:

assistant: SELECT "Tie no" FROM "Table" WHERE "Away team" = 'Hartlepool United';