diff --git a/test_ui.lua b/test_ui.lua
new file mode 100644
index 0000000..64dd99b
--- /dev/null
+++ b/test_ui.lua
@@ -0,0 +1,33 @@
+require("oct_utils")
+require("termbox_defs")
+require("ui")
+
+--textbox = oct_tb_sprite_new()
+textbox = {}
+
+function oct_init()
+   -- textbox["x"] = 50
+   -- textbox["y"] = 20
+   -- textbox["shape"] = "___________"
+   -- textbox["fg"] = TB_RED
+   textbox1 = create_textbox("textbox1", 50, 20, 20)
+   textbox2 = create_textbox("textbox2", 50, 22, 20)
+   textbox3 = create_textbox("textbox3", 50, 24, 20)
+   register_textbox(textbox1)
+   register_textbox(textbox1)
+   register_textbox(textbox2)
+   register_textbox(textbox3)
+   unregister_textbox(textbox2)
+   unregister_textbox(textbox2)
+
+   return OCT_NOT_NEEDS_NETWORKING, OCT_NEEDS_TERMBOX
+end
+
+function oct_loop(key, ch)
+   textbox_contents = handle_textbox(key, ch)
+   if (textbox_contents)
+   then
+	  OCT_LOG_DEBUG("Received string from textbox: " .. table_to_string(textbox_contents))
+   end
+   
+end
diff --git a/ui.lua b/ui.lua
new file mode 100644
index 0000000..577314e
--- /dev/null
+++ b/ui.lua
@@ -0,0 +1,129 @@
+-- Contains user interface elements
+require("oct_utils")
+require("termbox_defs")
+
+
+-- visible_textboxes is a global list of all textboxes we can cycle through
+-- it is, in principle, a circular list
+-- the top of the list is the currently selected textbox
+-- upon a switch (i.e. TAB key), the list is rotated
+registered_textboxes = {}
+
+function create_textbox(id, pos_x, pos_y, max_length)
+   t = oct_tb_sprite_new()
+   t["x"] = pos_x
+   t["y"] = pos_y
+   t["shape"] = string.rep("_", max_length) -- what is displayed to user
+   t["fg"] = TB_WHITE
+
+   local textbox = {}
+   textbox["sprite"] = t
+   textbox["contents"] = "" -- what is returned when box is submitted
+   textbox["max_length"] = max_length
+   textbox["id"] = id
+   return textbox
+end
+
+function update_registered_textboxes_appearance()
+   -- textbox at front is focused, set to green
+   registered_textboxes[1]["sprite"]["fg"] = TB_GREEN
+   -- set all other textboxes to unfocused (white colored)
+   for i=2,#registered_textboxes
+   do
+	  registered_textboxes[i]["sprite"]["fg"] = TB_WHITE
+   end   
+end
+
+function register_textbox(textbox)
+   already_registered = false;
+   for i=1,#registered_textboxes
+   do
+	  if (registered_textboxes[i] == textbox)
+	  then
+		 already_registered = true
+	  end
+   end
+
+   if (already_registered)
+   then
+	  OCT_LOG_WARNING("Attempted to register an already-registered textbox")
+   else
+	  table.insert(registered_textboxes, 1, textbox)
+   end
+  
+   update_registered_textboxes_appearance()
+end
+
+function unregister_textbox(textbox)
+   removed = false
+   for i=1,#registered_textboxes
+   do
+	  if (registered_textboxes[i] == textbox)
+	  then
+		 table.remove(registered_textboxes, i)
+		 textbox["sprite"]["fg"] = TB_WHITE
+		 removed = true
+	  end
+   end
+   if not removed
+   then
+	  OCT_LOG_WARNING("Attempted to unregister an unregistered textbox")
+   end
+   update_registered_textboxes_appearance()
+end
+
+function textbox_contents_to_shape(contents, max_length)
+   l = string.len(contents)
+   ret_str = ""
+   if (l < max_length+1)
+   then
+	  ret_str = contents
+	  n_underscores = max_length - l
+	  ret_str = ret_str .. string.rep("_", n_underscores)
+   else -- show only the last max_length characters
+	  ret_str = string.sub(contents, -max_length)
+   end
+   return ret_str
+end
+
+
+function handle_textbox(key, ch)
+   local to_return = nil
+   -- Convert ch from a character code to a character
+   ch = string.char(ch)
+   
+   -- if nothing was pressed, ch is '\0' (null byte)
+   if (ch ~= '\0')
+   then
+	  -- Update the contents of the textbox, this isn't displayed by default
+	  registered_textboxes[1]["contents"] = registered_textboxes[1]["contents"] .. ch
+   end
+
+   if (key == TB_KEY_BACKSPACE2 or key == TB_KEY_BACKSPACE)
+   then
+	  registered_textboxes[1]["contents"] = string.sub(registered_textboxes[1]["contents"], 1, string.len(registered_textboxes[1]["contents"])-1)
+   end
+
+   -- Update the user-visible sprite
+   registered_textboxes[1]["sprite"]["shape"] = textbox_contents_to_shape(registered_textboxes[1]["contents"], registered_textboxes[1]["max_length"])
+
+   -- Submit our registered textboxes
+   if (key == TB_KEY_ENTER)
+   then
+	  to_return = {}
+	  for i=1,#registered_textboxes 
+	  do
+		 curr = registered_textboxes[i]
+		 to_return[curr["id"]] = curr["contents"]
+	  end
+   end
+
+   -- Rotate the registered textboxes
+   if (key == TB_KEY_TAB)
+   then
+	  table.insert(registered_textboxes, 1, table.remove(registered_textboxes))
+	  update_registered_textboxes_appearance()
+   end
+   
+   return to_return
+end