Set or get the volume level for an audio device.
level A number specifying the volume level.
The volume level is a value between 0 and 255 inclusive. A value of 0 specifies no sound and a value of 255 specifies the loudest volume.
When parameter level is not specified then the current volume level is displayed.
When no suitable audio device is installed or the installed audio device does not support software volume control then a suitable error message is displayed.