[Problem]Take function in Quest not working

quest pietre begin
state start begin
function extract_metin_stone_from_pos( pos )
item.select_cell( pos )

local info_name = {}
local info_pos = {}

for i=0 , 2 do
local val = item.get_socket(i)

if val > 2 and val != 28960 then
table.insert( info_name , item_name(val) )
table.insert( info_pos , i )
end
end

table.insert( info_name , "Back" )

local s = select_table( info_name )

if s == table.getn( info_name ) then
return
end

if pc.get_empty_inventory_count() <= 0 then
say("You're in too little space for the stone inventory.")
say("")
return
end

pc.give_item2( item.get_socket( info_pos[s] ) )
item.set_socket( info_pos[s] , 1 )
end

when 20093.take begin
say("With this object you can remove any stone")
say("of yours items. Select the item from")
say("which you want to remove the stone and then")
say("select the stone you want to remove.")
say("")

local data = pc.get_socket_items()

local sel_item = {}

if table.getn( data ) > 6 then
local sel_pos = {}

while table.getn(data) > 0 do
for i=1 , math.min(6 , table.getn(data)) do
table.insert( sel_item , i , data[1][1] )
table.insert( sel_pos , i , data[1][2] )
table.remove( data , 1 )
end

if table.getn( sel_item ) < 6 then
table.insert( sel_item , "Back" )
else
table.insert( sel_item , "Next" )
end

local s = select_table( sel_item )

if s == table.getn( sel_item ) then
while table.getn( sel_item ) > 0 do
table.remove( sel_item )
end

while table.getn( sel_pos ) > 0 do
table.remove( sel_pos )
end
else
pietre.extract_metin_stone_from_pos( sel_pos[s] )
break
end
end
else
for i=1 , table.getn( data ) do
table.insert( sel_item , data[i][1] )
end

table.insert( sel_item , "Back" )
local s = select_table( sel_item )

if s != table.getn( sel_item ) then
pietre.extract_metin_stone_from_pos( data[s][2] )
end
end
end
end
end