A method for controlling a display device, comprising: accessing a website; receiving, at the display device from the accessed website, first shortcut key information, which is predetermined in order to execute a specific function on a webpage; generating an icon representing a first shortcut key based on the first shortcut key information; displaying, on a display, the generated icon in a prescribed section of the webpage; receiving a signal selecting the icon; displaying, on the display, a graphical user interface, GUI, that includes displayed information of the first shortcut key in response to the signal selecting the icon, wherein the displayed information corresponds to key information of the first shortcut key and function information on a function being realized by the first shortcut key, whereby the function information is provided to a user via a text, an animation or a sound, in response to an input selecting specific information displayed on the GUI; receiving an input to setup a second shortcut key based on the displayed information; and mapping the first shortcut key to the second shortcut key and storing the mapped first and second shortcut keys such that the second shortcut key performs the same function as the first shortcut key, wherein the first shortcut key corresponds to a specific hard key or a prescribed key on a virtual keyboard to perform the specific function within the webpage, and wherein the first shortcut key and the second shortcut key are different from each other, and wherein the first shortcut key corresponds to a key on a first external input device and the second shortcut key corresponds to a key on a second external input device different than the first external input device, and wherein further the external input devices corresponds to at least one of a remote controller, mobile phone, tablet or keyboard. accessing a website; receiving, at the display device from the accessed website, first shortcut key information, which is predetermined in order to execute a specific function on a webpage; generating an icon representing a first shortcut key based on the first shortcut key information; displaying, on a display, the generated icon in a prescribed section of the webpage; receiving a signal selecting the icon; displaying, on the display, a graphical user interface, GUI, that includes displayed information of the first shortcut key in response to the signal selecting the icon, wherein the displayed information corresponds to key information of the first shortcut key and function information on a function being realized by the first shortcut key, whereby the function information is provided to a user via a text, an animation or a sound, in response to an input selecting specific information displayed on the GUI; receiving an input to setup a second shortcut key based on the displayed information; and mapping the first shortcut key to the second shortcut key and storing the mapped first and second shortcut keys such that the second shortcut key performs the same function as the first shortcut key, wherein the first shortcut key corresponds to a specific hard key or a prescribed key on a virtual keyboard to perform the specific function within the webpage, and wherein the first shortcut key and the second shortcut key are different from each other, and wherein the first shortcut key corresponds to a key on a first external input device and the second shortcut key corresponds to a key on a second external input device different than the first external input device, and wherein further the external input devices corresponds to at least one of a remote controller, mobile phone, tablet or keyboard.