Change read/write permissions for files

[Cyrebo]

Hi i am still new to the Linux system having just installed Kubuntu 12.10 and im having trouble changing user permissions for files. I am programming a program with database queries and it seems to not have write permissions, only read because i can read the file. I right-click->properties->permissions the choose can read and write for all users but when i close it and go back it says only can read for all users. Is there a way to make it so that my program can write to this file? Oh, and the file is on my usb drive,should that be a problem and if so, how can it be so that my program has permission to write to it?

[claracc]

I think, it is important for what you are doing to understand permissions file system: https://help.ubuntu.com/community/FilePermissions