Please use Screenshots for your report.

Dear Members,
If you wish to report on someone, it can be done by using Screenshot as a proof.
If not, the member/s you reported on won't be taken care of.

- How to use Screenshot? -
While ingame, use CTRL + PR1SC (or PRINT for some keyboards) to capture.
Exit the game (or just use ALT + TAB), and enter to Paint or Photoshop programs.
Use the CTRL + V to paste your capture.
Upload your capture to one of these sites: ImageShack.us , TinyPic.com.

- Another way to use Screenshot -
While ingame, one of the maplestory defult keys are letting you use Screenshot.
Just press it and do everything else from above.