help with psp memory stick

when i was putting games on my memory stick my pc said i needed to format it. instead of me formatting it, my impatient cousin took the psp out of usb mode, and the psp wouldnt read it. i tryed to make it go back into usb mode but it keeps saying that no memory stick is inserted.
the memory stick is a 4gb memory stick pro duo.

If you have a memory stick card and a card reader try that and reformat the stick.And next time, before adding games-use the psp's internal memory stick formatter do it so it adds in the folders :)

thanks, but ill have to find buy another pro duo card reader though, are you sure this would work based on personal experience?? i just wanna know because i dont want to buy a card reader and then have to come up with 30$ for a memory stick...