Scottish independence: Politicians debate border controls
19 February 2014 Last updated at 13:54 GMT
Four politicians, Patrick Harvie (Scottish Greens), Ruth Davidson (Scottish Tories), Stewart Hosie (SNP) and Jenny Marra (Scottish Labour) answered audience questions on issues connected to the referendum debate.
They were taking part in the second of a series of BBC debates on Scotland's future.
Voters in Scotland go to the polls on 18 September where they will be asked the "yes/no" question: "Should Scotland be an independent country?"
The next debate takes place in Kirkcaldy in Fife on Tuesday, 18 March.