turbo pascal question

Hi,
my brother asked me about this, now I ask you.
This should work for FreePascal, but not for Borland Pascal 6.0 or 7.0 -
WHY?
Any suggestions or workarounds?

Error in TP 7: Invalif function result type (see <--)

type
feld = (leer, NF, TF, SK, TP, A); {FELDART}
aufbau = record {EIGENSCHAFTEN DER SPIELFELDER}
art : feld; {FELDART}
entdeckt : boolean; {TRUE WENN VOM USER FELD BETRITT}
end;
laby = array [1..lab_xSize, 1..lab_ySize] of aufbau;
{LABYRINTHAUFBAU}

function createlab(var aus_x, aus_y : integer) : laby; <--
.......


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