title: NameError: name 'event' is not defined in Tkinter
body: <p>I'm writing a code in Python using tkinter to get a value from a combo box, after that I use this value in click event of a button. But when I run this code I got this error</p>
  <p>&quot;NameError: name 'event' is not defined&quot;</p>
  <p>My code is like this</p>
  <pre><code>from tkinter import *
  from tkinter.ttk import *    
  from matplotlib.font_manager import FontProperties
  
  font = FontProperties()
  font.set_family('serif')
  font.set_name('Times New Roman')
  font.set_style('normal')  
  
      
  window = Tk()
   
  window.title(&quot;CCE Tool&quot;)
   
  tab_control = Notebook(window) 
  
  tab1 = Frame(tab_control) 
  tab2 = Frame(tab_control)
   
  tab_control.add(tab1, text='Regional') 
  tab_control.add(tab2, text='Plot')
  
  Filee_Tab1=Entry(tab1 ,width=70 , text='Enter adress of database')
  Filee_Tab1.grid(column=1, row=0) 
   
  lbl1_Tab1 = Label(tab1, text= 'Input data address') 
  lbl1_Tab1.grid(column=0, row=0)  
  
  
  
  def combo3_Tab1_click(event):
      global X # Setting select_sheet to global, so it can be modified
      X = combo3_Tab1.get()
      return X
  
  
  def clicked_btn2_Tab1():
  
    X = combo3_Tab1_click(event)     
    return 0
  
  combo3_Tab1 = Combobox(tab1, state=&quot;readonly&quot;)  
  # combo3_Tab1.current(1) 
  combo3_Tab1['values']= [&quot;1&quot;,&quot;2&quot;,&quot;3&quot;]
  combo3_Tab1.grid(column=1, row=4) 
  combo3_Tab1.bind(&quot;&lt;&lt;ComboboxSelected&gt;&gt;&quot;, combo3_Tab1_click)
  
  btn2_Tab1 = Button(tab1,text='Run CNN', command=clicked_btn2_Tab1)
  btn2_Tab1.grid(column=0,row=7)
  
  tab_control.pack(expand=1, fill='both')     
  
  window.geometry('900x500')
   
  window.mainloop()
  </code></pre>
  <p>How can I fixed this error
  Thank you</p>