title: Two Button named add1 and add2 don't work
body: <p>I'm a new programmer so sorry for any blunders. I'm creating the screens for an Italian quiz game. In LA COPERTINA screen, the buttons that should be used to increase or decrease the amount of money by 500 euros do not work and also 500 euros already appear while the tot1s variable is set to 0. What could be the error? add1 and add2 button call sottrai1 and aggiungi1 functions, but they don't work. I need to return tot1 cause it will update continuously during the game.</p>
  <pre><code>import tkinter as tk
  from tkinter import *
  from tkinter import ttk
  
  from PIL import Image, ImageTk
  from tkinter.font import Font
  
  class schermoiniziale(tk.Frame):
      def __init__(self, master, **kw):
          # need to call __init__() of inherited class
          super().__init__(master, **kw)
          global g1, g2, g3, gio1, gio2, gio3, tot1, tot2, tot3, tot1s
          
          self.gio1=tk.StringVar()
          self.gio2=tk.StringVar()
          self.gio3=tk.StringVar()
          # stile per la formattazione del pulsante INIZIA
          style = ttk.Style()
          # configura lo sfondo della finestra che altrimenti sarebbe bianco
          self.configure(background=&quot;#000098&quot;)
          # definizione titolo e campi della finestra principale
          Titolo  = tk.Label(self, text=&quot;     SUPERFLASH     &quot;, font=&quot;DS-Digital 100 bold italic&quot;, background='#000098', foreground='white')
          myLabel1 = tk.Label(self, text=&quot;Concorrente 1:&quot;, font=&quot;Arial 30 bold&quot;, background='#000098', foreground='white')
          myLabel2 = tk.Label(self, text=&quot;Concorrente 2:&quot;, font=&quot;Arial 30 bold&quot;, background='#000098', foreground='white')
          myLabel3 = tk.Label(self, text=&quot;Concorrente 3:&quot;, font=&quot;Arial 30 bold&quot;, background='#000098', foreground='white')
          self.g1 = tk.Entry(self, textvariable=self.gio1, font=&quot;Arial 20&quot;, width=50)
          self.g2 = tk.Entry(self, textvariable=self.gio2, font=&quot;Arial 20&quot;, width=50)
          self.g3 = tk.Entry(self, textvariable=self.gio3, font=&quot;Arial 20&quot;, width=50)
          Titolo.pack()
          myLabel1.pack(pady=2)
          self.g1.pack(pady=2)
          self.g1.focus()
          myLabel2.pack(pady=2)
          self.g2.pack(pady=2)
          myLabel3.pack(pady=2)
          self.g3.pack(pady=2)
          
          Inizio = ttk.Button(self, text=&quot;INIZIA&quot;, command=self.lacopertina, style=&quot;big.TButton&quot;)
          style.configure('big.TButton', font=(None, 20), foreground=&quot;black&quot;)
          Inizio.pack(padx=0, pady=10)
              
      def lacopertina(self):
          
          
          global tot1,tot1s    
          tot1s=&quot;0&quot;
          tot1=0
          tot2=0
          tot3=0
          root2 = tk.Toplevel()
          nome1= self.gio1.get()
          nome2= self.gio2.get()
          nome3= self.gio3.get()
          self.tot1s=tk.StringVar()
          self.tot2s=tk.StringVar()
          # titolo finestra
          root2.title(&quot;LA COPERTINA&quot;)
          # finestra principale
          canvas1=Canvas(root2, width=1185, height=625, bg='#000098')
          canvas1.place(x=0, y=148)
          # finestra dei punteggi
          canvas2=Canvas(root2, width=300, height=573, bg='#000000')
          canvas2.place(x=1190, y=0)
          # finestra pulsante carte
          canvas4=Canvas(root2, width=300, height=200, bg='#01ebe8')
          canvas4.place(x=1190, y=573)
          # finestra immagine del titolo
          canvas3=Canvas(root2, width=1185, height=155)
          canvas3.place(x=0, y=0)
          load = Image.open(&quot;lacopertina.jpg&quot;)
          photo= ImageTk.PhotoImage(load)
          canvas3.create_image(593,74, image=photo)
          
          # etichette concorrenti
          NomeGiocatore1= tk.Label(canvas2, text=&quot;Giocatore1:&quot;, font=(&quot;Arial&quot;, 15),bg='#000', fg='#fff')
          NomeGiocatore1.place(x=20, y=20)
          NomeGiocatore2= tk.Label(canvas2, text=&quot;Giocatore2:&quot;, font=(&quot;Arial&quot;, 15),bg='#000', fg='#fff')
          NomeGiocatore2.place(x=20, y=200)
          NomeGiocatore3= tk.Label(canvas2, text=&quot;Giocatore3:&quot;, font=(&quot;Arial&quot;, 15),bg='#000', fg='#fff')
          NomeGiocatore3.place(x=20, y=380)
          # funzioni cambio ammontare
          def sottrai1(tot1):
              tot1=tot1-500
              #tot1s=str(tot1)
              myLabel41.config(text=tot1)
              return tot1
          def aggiungi1(tot1):
              tot1+=500
              #tot1s=str(tot1)
              myLabel41.config(text=tot1)
              return tot1
          
          
          # etichette con i nomi dei giocatori e ammontare in denaro
          myLabel4 = tk.Label(canvas2, text=nome1, font=(&quot;Arial&quot;, 15))
          myLabel4.place(x=20, y=60)
          myLabel40 = tk.Label(canvas2, text=&quot;€ &quot;, font=(&quot;Arial&quot;, 15),bg='#000', fg='#e8f100')
          myLabel40.place(x=20, y=100)
          myLabel41 = tk.Label(canvas2, text=tot1s, font=(&quot;Arial&quot;, 15),bg='#000', fg='#e8f100')
          myLabel41.place(x=55, y=100)
          myLabel5 = tk.Label(canvas2, text=nome2, font=(&quot;Arial&quot;, 15))
          myLabel5.place(x=20, y=240)
          myLabel50 = tk.Label(canvas2, text=&quot;€ &quot;, font=(&quot;Arial&quot;, 15),bg='#000', fg='#e8f100')
          myLabel50.place(x=20, y=280)
          myLabel51 = tk.Label(canvas2, text=tot2, font=(&quot;Arial&quot;, 15),bg='#000', fg='#e8f100')
          myLabel51.place(x=55, y=280)
          myLabel6 = tk.Label(canvas2, text=nome3, font=(&quot;Arial&quot;, 15))
          myLabel6.place(x=20, y=420)
          myLabel60 = tk.Label(canvas2, text=&quot;€ &quot;, font=(&quot;Arial&quot;, 15),bg='#000', fg='#e8f100')
          myLabel60.place(x=20, y=460)
          myLabel61 = tk.Label(canvas2, text=tot3, font=(&quot;Arial&quot;, 15),bg='#000', fg='#e8f100')
          myLabel61.place(x=55, y=460)
          # pulsanti che modificano l'ammontare in denaro
          add1 = tk.Button(canvas2, text=&quot;-&quot;, command=sottrai1(tot1), font=(&quot;Arial&quot;, 10))
          add1.place(x=20, y=140)
          add2 = tk.Button(canvas2, text=&quot;+&quot;, command=aggiungi1(tot1), font=(&quot;Arial&quot;, 10))
          add2.place(x=50, y=140)
                  
            
          root2.geometry(&quot;1500x783&quot;)
          root2.mainloop()
              
          
  def main():
      # need to create the root window before creating other widget
      
      root = tk.Tk()
      
      root.title(&quot;SUPERFLASH&quot;)
      root.geometry(&quot;800x488&quot;)
      root.iconbitmap('icona.ico')
      
      #loadschermo1=Image.open(&quot;schermo2.jpg&quot;)
      #photoschermo1=ImageTk.PhotoImage(loadschermo1)
      #canvasschermo1.create_image(400,578, image=photoschermo1)
  
      
        
      # pass root window as the parent of the widget
      frame = schermoiniziale(root)
      frame.pack(padx=0, pady=0)
      
      # start the tkinter mainloop
      root.mainloop()
  
  if __name__== &quot;__main__&quot;:
      main()
  </code></pre>