Making ents dissappear during certain rounds.

I’m not a mapper or a very good coder, but after some attempts I tried making an ent named “dis_wall” and with each mode (Build/Fight) it dissappears and comes back, but the collision groups dont seem to work. Is this something I should do in the map itself? or can I do it in LUA?

Code:
[lua]
function GM:SwitchMode()
for k,v in pairs(player.GetAll()) do
if v:Alive() then
v:StripWeapons()
v:KillSilent()
end
end
if FightMode then
CountDownStarted = CurTime()
FightMode = false
for k,v in pairs(ents.FindByName(“dis_wall”)) do
v:SetColor(255,255,255,255)
v:SetCollisionGroup(COLLISION_GROUP_NONE)
end
timer.Create(“FightBuildSwitch”,BuildTimeAllowed,1,GAMEMODE.SwitchMode)
elseif !FightMode then
CountDownStarted = CurTime()
FightMode = true
for k,v in pairs(ents.FindByName(“dis_wall”)) do
v:SetColor(0,0,0,0)
v:SetCollisionGroup(COLLISION_GROUP_WORLD)–This blocks bullets and stuff, but not players. Should I remove?
end
timer.Create(“BuildFightSwitch”, FightTimeAllowed, 1, GAMEMODE.SwitchMode)

end

end
[/lua]

Can someone help me? Thanks.

-bump- Please. (Usually I don’t do that, but it’s pretty important and I haven’t been able to think of anything.

Try use ShouldCollide hook.
[lua] hook.Add( “ShouldCollide”, “SetWallCollide”, function( ent1, ent2 )
if ( ent1:GetClass() == “dis_wall” or ent2:GetClass() == “dis_wall” ) and FightMode then
return false
end
end )[/lua]