Help, i'm new to dvd recording

I just bought a Panasonic DMR-ES10 dvd recorder in Canada, i recorded some home made clips to a dvd-r using the the dvd recorder. After that i sent them to my relatives in China, but when they tried playing them they don’t seem to work. Is this problem related to regionally stuff? Is there a way i can fix this? Thanks.

Not an expert, but I assume Canada is NTSC and I think China might be PAL. On the other hand, your friend’s player may not be able to read your recordable discs. What happens when he/she puts one of your discs in his machine?