A device comprising a processor to: set a plurality of layout modes to organize and display the messages exchanged among devices in a chatting session; select a layout mode from among the plurality of layout modes; identify whether a first message is a main message; extract message parameters from a second message; identify whether a second message is a child message or a branch message from the first message; display the first message and the second message on a displayer by organizing the first and second massages; extract message parameters from a third message; identify whether a third message is a child message to the second message or a branch message from the first message using the extracted message parameters of the second message; and display the first, second and third messages on a displayer by organizing the first, second and third massages in the hierarchical structured fashion.