How did Jackie Chan get the name 'Jackie'?

Jackie Chan got the name "Jackie" when he was working construction in Australia. On the first day of work he was asked for his name. The person (Jack) who got him the job realised that "Kong-sang" would be too difficult, said "Call him Jack". When people said 'But you are Jack, how will we tell you apart?" Jack said "I'm Big Jack, he is Little Jack." 'Little Jack' quickly changed to 'Jackie'. Jackie liked the name and soon every one, including his parents were calling him 'Jackie'.