21. The method of claim 18 , further comprising: decreasing a number of chat messages displayed in the messenger chat window based on a number of inputs received for displaying chat messages in response to a notification that a chat message has been received from the second terminal.
18. A method for controlling a messenger chat application in a first portable terminal, the method comprising: displaying a messenger chat window of the messenger chat application on a display of the first portable terminal after receiving an indication at the first portable device to execute the messenger chat application; receiving, from a second terminal, a first chat message corresponding to a second chat message previously transmitted from the first portable terminal to the second portable terminal using the messenger chat application, the first chat message including index information associated with the second chat message; determining whether the second chat message is currently displayed in the messenger chat window based on the index information associated with the second chat message received from the second terminal; if the second chat message is currently displayed in the message chat window, displaying the first chat message directly adjacent to the second chat message in the message chat window; if the second chat message is not currently displayed in the message chat window, displaying a notification that the first chat message has been received; and if an input for displaying the first chat message is received in response to the notification that the first chat message has been received, retrieving the second chat message associated with the first chat message and displaying the first chat message and the second chat message within the messenger chat window after the input for displaying the first chat message is received.