11. A character input method for automatically switching an input mode in a terminal having a touch screen the character input method comprising: assigning character groups, each of which includes at least two characters, to at least two key regions acquired by dividing a region of the touch screen and displaying the character groups in the corresponding key regions based on one-to-one correspondence; if a press event occurs in one of the key regions, determining whether a drag event occurs prior to occurrence of a release event; if it is determined that the drag eve occurs, switching to a separate input mode for inputting one of characters of a corresponding character group; upon execution of the separate input mode, checking a distance and a direction of the drag event; displaying a character corresponding to the checked distance and direction of the drag event from among characters of the key region where the press event occurs; and if the release event occurs when the character is displayed, outputting the displayed character.
11. A character input method for automatically switching an input mode in a terminal having a touch screen the character input method comprising: assigning character groups, each of which includes at least two characters, to at least two key regions acquired by dividing a region of the touch screen and displaying the character groups in the corresponding key regions based on one-to-one correspondence; if a press event occurs in one of the key regions, determining whether a drag event occurs prior to occurrence of a release event; if it is determined that the drag eve occurs, switching to a separate input mode for inputting one of characters of a corresponding character group; upon execution of the separate input mode, checking a distance and a direction of the drag event; displaying a character corresponding to the checked distance and direction of the drag event from among characters of the key region where the press event occurs; and if the release event occurs when the character is displayed, outputting the displayed character. 15. The character input method of claim 11 , wherein a text input mode is a mode using a T9 input method.