why do i have this bug and how to fix it?

[xvshengjie]

hello, thank you for your code, i want to know how to fix this bug. Again, thx.

[QingtianZhang]

Did you modify the 'filename' according to the file's name and storage location on your PC?

[xvshengjie]

ohhhhhh, my fault. It worked, thanks bro.