diff --git a/libworld.lua b/libworld.lua
index 6488b91..5b61cdc 100644
--- a/libworld.lua
+++ b/libworld.lua
@@ -1,13 +1,16 @@
+-- LibWorld - Copy and paste world area, store in digital type.
+-- Author: Github/Kiritow
+
 local component=require("component")
 
--- Hardware check
-local debugcard=component.debug
-
-if(debugcard==nil) then
-    error("This program require debug card.")
-end
-
+-- Copy an area. returns a table contains area info.
+-- Can be serialized and stored in files.
 function CopyArea(ax,ay,az,bx,by,bz)
+    local debugcard=component.debug
+    if(debugcard==nil) then
+        error("This program require debug card.")
+    end
+
     local box={}
     if(ax>bx) then ax,bx=bx,ax end
     if(ay>by) then ay,by=by,ay end
@@ -29,6 +32,98 @@ function CopyArea(ax,ay,az,bx,by,bz)
                 t.z=z-az
                 t.id=world.getBlockId(x,y,z)
                 t.meta=world.getMetadata(x,y,z)
+                local xnbt=world.getTileNBT(x,y,z)
+                if(xnbt~=nil) then
+                    t.nbt=xnbt
+                end
+                table.insert(box,t)
+            end
+        end
+    end
+    return box
+end
+
+-- Act like CopyArea, but no air blocks are recorded.
+function CopyAreaWithoutAir(ax,ay,az,bx,by,bz)
+    local debugcard=component.debug
+    if(debugcard==nil) then
+        error("This program require debug card.")
+    end
+
+    local box={}
+    if(ax>bx) then ax,bx=bx,ax end
+    if(ay>by) then ay,by=by,ay end
+    if(az>bz) then az,bz=bz,az end
+    local total=(bx-ax+1)*(by-ay+1)*(bz-az+1)
+    local cnt=0
+    local world=debugcard.getWorld()
+    for x=ax,bx,1 do
+        for y=ay,by,1 do
+            for z=az,bz,1 do
+                cnt=cnt+1
+                print("Adding Block (" .. x .. "," .. y .. "," .. z .. ") " .. cnt .. " of " .. total .. " [" .. cnt*100/total .. "%]")
+                if(not world.isLoaded(x,y,z)) then
+                    error("Block (" .. x .. "," .. y .. "," .. z .. ") is not loaded.")
+                end
+                local t={}
+                t.id=world.getBlockId(x,y,z)
+                if(t.id~=0) then
+                    t.x=x-ax
+                    t.y=y-ay
+                    t.z=z-az
+                    t.meta=world.getMetadata(x,y,z)
+                    local xnbt=world.getTileNBT(x,y,z)
+                    if(xnbt~=nil) then
+                        t.nbt=xnbt
+                    end
+                    table.insert(box,t)
+                end
+            end
+        end
+    end
+    return box
+end
+
+-- Act like CopyArea, but store block ID in string type.
+function CopyAreaStrID(ax,ay,az,bx,by,bz)
+    local debugcard=component.debug
+    if(debugcard==nil) then
+        error("This program require debug card.")
+    end
+    
+    local box={}
+    if(ax>bx) then ax,bx=bx,ax end
+    if(ay>by) then ay,by=by,ay end
+    if(az>bz) then az,bz=bz,az end
+    local total=(bx-ax+1)*(by-ay+1)*(bz-az+1)
+    local cnt=0
+    local world=debugcard.getWorld()
+    for x=ax,bx,1 do
+        for y=ay,by,1 do
+            for z=az,bz,1 do
+                cnt=cnt+1
+                print("Adding Block (" .. x .. "," .. y .. "," .. z .. ") " .. cnt .. " of " .. total .. " [" .. cnt*100/total .. "%]")
+                if(not world.isLoaded(x,y,z)) then
+                    error("Block (" .. x .. "," .. y .. "," .. z .. ") is not loaded.")
+                end
+                local t={}
+                t.x=x-ax
+                t.y=y-ay
+                t.z=z-az
+                local blkstate=world.getBlockState(x,y,z)
+                local blklftidx=string.find(blkstate,"[",1,true)
+                if(blklftidx~=nil) then
+                    -- minecraft:grass[snowy=false]
+                    t.id=string.sub(blkstate,1,blklftidx-1)
+                else
+                    -- minecraft:gold_block
+                    t.id=blkstate
+                end
+                t.meta=world.getMetadata(x,y,z)
+                local xnbt=world.getTileNBT(x,y,z)
+                if(xnbt~=nil) then
+                    t.nbt=xnbt
+                end
                 table.insert(box,t)
             end
         end
@@ -41,9 +136,13 @@ function PasteArea(box,ax,ay,az)
     local world=debugcard.getWorld()
     for k,v in ipairs(box) do
         print("Pasting to (" .. ax+v.x .. "," .. ay+v.y .. "," .. az+v.z .. ")")
-        world.setBlock(ax+v.x,ay+v.y,az+v.z,v.id,0)
+        world.setBlock(ax+v.x,ay+v.y,az+v.z,v.id,v.meta)
+        if(v.nbt~=nil) then
+            world.setTileNBT(x,y,z,v.nbt)
+        end
         cnt=cnt+1
     end
+    print("Pasted " .. cnt .. " blocks.")
     return cnt  
 end