PURPOSE: To improve operability for input operations by providing a holding means to successively hold character information and a user interface means.

CONSTITUTION: This system is composed of a user interface means 1, holding means 2 to successively hold the inputted character information, display means 3 to display the character information or an alarm message, and command storing means 4 previously storing command names and commands in a table form (as a command table, for example,) while making the command names and the commands correspondent one and another. When any event to be warned such as input error or time-out, etc., occurs, the user interface means 1 displays the alarm message at the display means 3, and the character information as the object of the event to be warned read from the holding means 2 is displayed at the display means 3 again. Thus, even when the alarm message is displayed, the inputted characters can be speedily corrected and operability can be improved.