Table: fa_cup_matches_13
Columns: tie_no
home_team
score
away_team
attendance

Question: What was the tie for the Crystal Palace team?
SQL: SELECT "tie_no" FROM fa_cup_matches_13 WHERE "home_team" = 'crystal palace'

Question: What is the attendance for No. 15 tie?
SQL: SELECT "attendance" FROM fa_cup_matches_13 WHERE "tie_no" = '15'