An input device is disclosed that includes a sensor for editing characters and text units. The sensor has an elongate configuration and is laterally-oriented with respect to sides of the input device. The input device also includes a plurality of keys for entering individual characters or multiple characters that form the text units. By contacting the sensor, an incorrectly-entered text unit may be selected and replaced with an intended text unit. In order to select the incorrectly-entered text unit, the sensor may be contacted in a position that corresponds with a position of the text unit with respect to a display screen.