1. A method of changing a display of a task for a portable communication apparatus capable of multi-processing a plurality of task and of providing a plurality of display regions for displaying data, the plurality of tasks including a communication task, the method comprising: upon receiving a call, generating an icon associated with one of the plurality of tasks, which is being displayed in a first display region, the first display region serving as a main display region; displaying the communication task in the first display region; and displaying the generated icon in a second display region, the second display region serving as a sub display region.