1. A portable device comprising: a display unit including a character window for displaying characters, wherein the character window includes a selecting character window for displaying a character line including at least one character, each character corresponding to virtual coordinates indicated by a cursor, and a selected character window for displaying a selected character, selected from the at least one character, on the selecting character window; a memory for storing the at least one character, each character having intrinsic virtual coordinates; a plurality of input keys for navigating the at least one character and selecting the selected character by using the virtual coordinates of the selected character; and a microprocessor for controlling a display of the selected character on the display unit according to an input of the input keys.