g_npc_dialog{ -- start of table
"conversation one.",
"conversation two."
} -- end of table

function pickuppable_init_name(e, name)
	g_pickuppable_name[e] = name
end

g_box_parameters = {["box1"]   = {height = 16, width = 20, length = 20},
					["box2"]   = {height = 16, width = 20, length = 30},
					["box3"]   = {height = 21, width = 25, length = 50},
					["Pot"]    = {height = 10, width = 10, length = 10},
					["Teapot"] = {height = 10, width = 10, length = 10}};

local name = g_pickuppable_name[e]
local HH   = g_box_parameters[name].height / 2

...

function pickuppable_is_overlapping(e1, e2)

	-- Check the entity is level first	
	if math.modf(GetEntityAngleX (e2)) ~= 0 or 
	   math.modf(GetEntityAngleZ (e2)) ~= 0 then return false end;
	
	local name = g_pickuppable_name[e2]	
	local H    = g_box_parameters[name].height
	local HW   = g_box_parameters[name].width  / 2
	local HL   = g_box_parameters[name].length / 2

	local Ent1 = g_Entity[e1]
	local Ent2 = g_Entity[e2]
		
	local DX, DY, DZ = Ent1.x - Ent2.x, Ent1.y - Ent2.y, Ent1.z - Ent2.z

	local ang1 = math.rad(Ent2.angley)
	local ang2 = math.atan(DX, DZ)
	local L    = math.sqrt(DX*DX + DZ*DZ)
	local NDX  = math.sin(ang2 - ang1) * L
	local NDZ  = math.cos(ang2 - ang1) * L
		
	return (DY  >  H  and DY  < H * 1.5 and
			NDZ > -HL and NDZ < HL      and 
			NDX > -HW and NDX < HW), DX, DZ
end

	pdist = GetPlayerDistance(e)
	if pdist <= 80 then
		TextCenterOnX(npc_namex,npc_namey,text_size,g_name[e])
		TextCenterOnX(npc_dialogx,npc_dialogy,text_size,g_npc_dialog[g_name[e]])
		Prompt(g_npc_dialog[g_name[e]])
	end

g_player_ingredients = 
{["ingredient1"]   = {quantity = 2},
{["ingredient2"]   = {quantity = 5},
{["ingredient3"]   = {quantity = 1};

g_player_ingredients[ingredient1].quantity + 1
--OR
g_player_ingredients[ingredient1].quantity - 3

g_player_ingredients['ingredient1'].quantity = g_player_ingredients['ingredient1'].quantity + 1

local eggs = g_player_ingredients['ingredient1']

eggs.quantity = eggs.quantity  + 1

 
for e, _ in pairs(g_Entity) do
     <do some processing, 'e' is the key into the g_Entity list>
end

function sort_pairs(list, order_given)
    -- collect the keys
    local keys = {}
    for k in pairs(list) do keys[#keys+1] = k end

    if order_given then
        table.sort(keys, function(a,b) return order_given(list, a, b) end)
    else
        table.sort(keys)
    end

    -- return the iterator function
    local i = 0
    return function()
        i = i + 1
        if keys[i] then
            return keys[i], list[keys[i]]
        end
    end
end

function big_escape_map_plot_enemies (x, y, xscale)
 	 
	local Px, Pz = g_PlayerPosX, g_PlayerPosZ
	-- player arrow is not centrally located in map so we need
	-- to work out edges of bezel in each direction
    local xmin, xmax = Px - 1800, Px + 731 / xscale
    local zmin, zmax = Pz - 840, Pz + 1400
	
	local enemy_list = {}
	
	for k, v in pairs(ai_soldier_state) do
	    if v ~= nil and 
		   g_Entity[k] ~= nil and 
		   g_Entity[k]['health'] > 0 and 
		   GetEntityVisibility(k) == 1 then
		   
		    local Ex, Ez = g_Entity[k]['x'], g_Entity[k]['z']
			
		    if Ex > xmin and Ex < xmax and Ez > zmin and Ez < zmax then
			
			    -- within bezel so lets add it to the list
				enemy_list[k] = {x = Ex, z = Ez}	
			end
		end
	end

...
   if enemy_list ~= nil then
		-- sort on distance from player
		local sorted_enemy_list = {}
		local xdiff, zdiff
		
		for k, _ in  pairs(enemy_list) do
		    xdiff = math.abs(enemy_list[k].x - Px)
			zdiff = math.abs(enemy_list[k].z - Pz)
			
			local rng_sqrd = xdiff*xdiff + zdiff*zdiff
			sorted_enemy_list[k] = rng_sqrd
		end

		for k, _ in sort_pairs(sorted_enemy_list, function(list,a,b) return list[a] < list[b] end) do
			
			if sprite_index < max_enemies then
				sprite_index = sprite_index + 1
			else
			    break
			end
			SetSpritePosition (sprites[sprite_index],
			                   x + ((enemy_list[k].x - Px) / step * xscale),
							   y -  (enemy_list[k].z - Pz) / step);
				              	   
			if ai_soldier_state[k] ~= 'alerted' and 
			   ai_soldier_state[k] ~= 'combat' then
			    -- Sort of neutral greeny blue colour
				SetSpriteColor (sprites[sprite_index], 80, 200, 200, 255)
		    else
			    -- Bright red
				SetSpriteColor (sprites[sprite_index], 255, 0, 0, 255)
			end
		end
	end
...