Why I can't copy files from my Mac to a USB stick?

[koko2blog]

I have an iBook G3 with Mac OS 10.3.9 and I placed there some files from my (Windows) Desktop because I wanted to format the hard drive.Now I am trying to copy the files back to the USB stick but I just can't!Every time I drag them, they return back.What is wrong?

[tompic823]

The USB stick might be in NTFS format. To change it, go into disk utility and click on the drive. go to the erase tab, select MS-DOS (FAT) and then click erase. it can now be used on macs and pc's