diff --git a/parts/gameFuncs.lua b/parts/gameFuncs.lua
index 40b830a7..a0eef690 100644
--- a/parts/gameFuncs.lua
+++ b/parts/gameFuncs.lua
@@ -183,7 +183,7 @@ end
 function setField(P,page)
     local F=FIELD[page]
     local height=0
-    for y=20,1,-1 do
+    for y=#F,1,-1 do
         if solidLine(F[y])then
             height=y
             break
diff --git a/parts/scenes/custom_field.lua b/parts/scenes/custom_field.lua
index a5e3853c..752cba22 100644
--- a/parts/scenes/custom_field.lua
+++ b/parts/scenes/custom_field.lua
@@ -184,7 +184,6 @@ function scene.keyDown(key)
         demo=not demo
     elseif key=="k"then
         ins(FIELD[page],1,{21,21,21,21,21,21,21,21,21,21})
-        FIELD[page][21]=nil
         SFX.play('blip')
     elseif key=="l"then
         local F=FIELD[page]