A device for organizing and displaying messages, the device comprising a processor, the processor being configured to: set a plurality of layout modes for organizing and displaying the messages exchanged among devices in a structured fashion; determine a layout mode for a chat session among the plurality of layout modes; display messages included in the chat session in the determined layout mode; and adjust the textbox-widths of all messages whenever a predetermined event occurs, wherein the event comprises at least one of a rotation of the device, sending or receiving of at least one message, and an input of at least one command for a scheme of displaying messages.