Seeking for a GetActorZ stuff solution --->please help

[DoomerMrT]

Ok so I have got a sector what has a 3D floor over it.I would like to activate a script only when the player is at/above the specified Z height.(so standing on the 3D foor)
The problem is, the 3D is a solid floor too and when I stand on it, it gives me a Z height of 0.So no matter if I am standing on or under the 3D floor, it will return 0.(Standing on the normal floor or on the 3D floor will return 0 Z-Height)


My script:
[spoiler]Script 50 (Void)
{
if(GetActorZ(0) - GetActorFloorZ(0) >= 148*65536)
{
setfont("Smallfont");
HudMessage(s:"\c[ContrastYG]You have found a secret area!";
HUDMSG_FADEOUT, 0, CR_LIGHTBLUE, 0.5, 0.45, 3.5);
LocalAmbientsound("DSRGATE",255);
SetLineSpecial(254,0);
}
else
{
Print (f:GetActorZ (0) - GetActorFloorZ (0)); //debug stuff
}
}[/spoiler]

[DoomerMrT]

Any ideas?This one mocks me well