diff --git a/src/gui.py b/src/gui.py
index 73ce20f..cf47b12 100644
--- a/src/gui.py
+++ b/src/gui.py
@@ -3,6 +3,7 @@ from tkinter import Tk
 from tkinter import Button, Label
 from .data import Message
 from src import sendkeys
+from typing import Callable
 
 
 class Gui(Tk):
@@ -31,12 +32,16 @@ class Gui(Tk):
             self.tabs[message.user][message.trade.item] = (tab, message)
             ttk.Label(tab, text=message.trade.item, style='BW.TLabel').pack(anchor='e', side='left')
             Label(tab, text=f'{message.trade.amount} {message.trade.currency}').pack(anchor='e', side='left')
-            Button(tab, text='Inv', command=lambda mess=message: self.inv_callback(message, tab)).pack(anchor='e', side='left')
+            self.add_button(tab=tab, text='Inv', callback=self.inv_callback, message=message)
+            # Button(tab, text='Inv', command=lambda mess=message: self.inv_callback(message, tab)).pack(anchor='e', side='left')
             Button(tab, text='Trade', command=lambda mess=message: self.trade_callback(message, tab)).pack(anchor='e', side='left')
             Button(tab, text='Ty',  command=lambda mess=message: self.ty_callback(message, tab)).pack(anchor='e', side='left')
             Button(tab, text='Wait',  command=lambda mess=message: self.wait_callback(message, tab)).pack(anchor='e', side='left')
             Button(tab, text='X',  command=lambda mess=message: self.destroy_tab(message, tab)).pack(anchor='e', side='left')
             self.tab_control.add(tab, text=message.user)
+            
+    def add_button(tab: ttk.Frame, text: str, callback: Callable, message: Message) -> None:
+            Button(tab, text=text, command=lambda mess=message: callback(message, tab)).pack(anchor='e', side='left')
 
     def start_move(self, event):
         self.x = event.x