How to avoid the warning message?

Dear,
During ReEnumerate the usb mass storage device, the warnning message \"The storage device that you just remover was not propery out away before being removed from this computer.Data ...\"  will pop out.To avoid appearing this  message, I must choose its icon and Eject it or Drag it to trash. So,I must do something like the action of Choose its icon and Eject it or drag it to trash. Do u have some idea of that?Thanks.