Generally, busy lamp fields are directly linked to the associated function keys. These keys are assigned to individual lamps and can be used for various functions. A steady light or a blinking light can be used to display the status of a telephone set. Often a steady light indicates an ongoing call and a blinking light an incoming call. Depending on this status, a call can be taken or picked up using the associated function key. If the line is free at the moment, it can be called by pressing the function key. In software-based PC solutions, these actions can be triggered by mouse click.