output device and the first video projector 211 selects the first portable computer 212 as its input device fig3 a illustrates a schematic view of a third embodiment that demonstrates another way of establishing of a sixth data connection 314 between a device 311 that can be a second video projector or another electronic device and a device 312 that can be a second portable computer or another electronic device the second video projector 311 includes a seventh data communication equipment 318 a and the second portable computer 312 includes a further seventh data communication equipment 318 b the sixth data connection 314 can be established between the seventh data communication equipment 318 a of the second second video projector 311 and the further seventh data communication equipment 318 b of the second portable computer 312 the sixth data connection 314 can be a wireless local area network wlan connection or another kind of data connection the seventh and further seventh data communication equipments 318 a 318 b are wlan transceivers or another kind of data communication equipment accordingly furthermore the second video projector 311 includes an eighth data communication equipment 319 a and the second portable computer 312 includes a further eighth data communication equipment 319 b in order to establish the sixth data connection 314 between the second video projector 311 and the second portable computer 312 it has to be authorized with a second tool 313 the second tool 313 includes a data memory 321 where data can be stored and read out the second tool 313 also includes a ninth data communication equipment 320 a seventh data connection 315 can be established between the ninth data communication equipment 320 of the second tool 313 and the eighth data communication equipment 319 a of.