here is one way to do it
Type CommonFields Field X#,Y#,Z# Field VX#,VY#,VZ# Field Entity Field RB Field Center End Type Type Man Field CommonFields.CommonFields Field O2 Field Health End Type Type Ship Field CommonFields.CommonFields Field Speed Field Fuel# Field Pilot Field Landed Field ThrustSound End Type SomeMan=New man SomeMan\CommonFields=New CommonFields SomeMan\CommonFields\x=100 Repeat If Rand(0,1)=1 UpdateFunction(SomeMan\CommonFields) Else UpdateFunction(SomeShip\CommonFields) End If Function UpdateFunction(CommonFields.CommonFields) PointEntity camera,CommonFields\entity Print CommonFields\x ;etc.