PURPOSE: To efficiently perform job processing by extracting a text number common for plural items from retrieved text numbers and displaying message text contents corresponding to this extracted common text number on a screen.

CONSTITUTION: The items of job contents such as related items A or D are displayed on a menu picture 1, and the various kinds of input and select operations can be performed by a mouse 4 provided with left and right buttons 4a and 4b. A message related to the item selected in the menu picture 1 is displayed on a display picture 5. When it is desired to know the message related to items A2 and D3, the mouse 4 is matched to the item A2 on the menu picture, and the item is selected by clicking the left button 4a. Next, the mouse 4 is matched to the item D3, and the item D3 is similarly selected. Concerning the selected items A2 and D3, the display color is changed, and the state of selecting them is shown. When the right button 4b is clicked, the related message is displayed.