you have to write it to the description.ext file in your own mission's folder.
If it does not exist, you have to create this file, let's say in Notepad, or any simple text editor software...
these lines are for set the following values( 0 is disable, 1 is enable)
showmap = 1
showGPS = 1
showCompass = 1
showWatch = 1
showNotepad = 1
yours is showmap=0