20. The touch sensitive display device of claim 1 , wherein the sensor unit delivers the sensed contact to the controller in a manner of converting to an electrical signal and wherein the controller detects the contact based on the electrical signal.
1. A touch sensitive display device, comprising: a display unit configured to display a graphic user interface; a sensor unit configured to sense a contact with the display unit; and a controller configured to control the display unit and the sensor unit, wherein the graphic user interface comprises a first area of a virtual keyboard and a second area of a digital content containing at least one text, wherein the controller: detects a first contact in the first area; displays and moves a word-selecting interface according to the first contact moving from the first area to the second area, converts at least one word within the at least one text to at least one soft button, the at least one word overlapped by the word-selecting interface in the digital content, displays the at least one soft button, the at least one soft button including the converted at least one word respectively, detects a second contact selecting a soft button among the at least one soft button, and inputs a word corresponding to the soft button into a text input box.