_tkinter.TclError: bad listbox index "": must be active, anchor, end, @x,y, or a number

from tkinter import*
tk=Tk()
tk.title("") #window title
tk["bg"] = "gray22" #color
tk.geometry("1000x900") #size
tk.resizable(width=False, height=True)     # no resize
canvas=Canvas(tk,width=700,height=400) 
canvas.pack()
img=PhotoImage(file="flowers.png")
img=PhotoImage(file="shari.png")
img=PhotoImage(file="mishka.png")
lbl2=Label()
lbl2.place(x=420,y=425)
#---
btn2=Button(text="Вих1д", command=tk.destroy)
btn2.place(x=678,y=500,width=175,height=50)
#текстове поле
ent=Entry()
ent.place(x=678,y=420,width=175,height=35)
#списоk
lbox=Listbox(height=3)
lbox.insert(END, "З днем народження")
lbox.insert(END, "З новім роком")
lbox.insert(END, "З 8 березня")
lbox.place(x=150,y=420,width=130,height=50)
#перемикачи
def btn1_click():
    global img
    if var.get()==1:
        img=PhotoImage(file="flowers.png")
    if var.get()==2:
        img=PhotoImage(file="shari.png")
    if var.get()==3:
        img=PhotoImage(file="mishka.png")
select = list(lbox.curselection())
lbl2.config(text= ent.get()+", "+lbox.get(select))
s=canvas.create_image(25,180,anchor=NW,image=img)
btn1=Button(text="Привітання", command=btn1_click)
btn1.place(x=150,y=500,width=100,height=50)
var=IntVar()
rbutton1=Radiobutton(tk,text="kviti",variable=var,value=1)
rbutton2=Radiobutton(tk,text="tort",variable=var,value=2)
rbutton3=Radiobutton(tk,text="shari",variable=var,value=3)
rbutton1.place(x=678,y=467,width=50,)
rbutton2.place(x=740,y=467,width=50)
rbutton3.place(x=801,y=467,width=52)