#Longevity
#Demonstrates text entry widget and the grid layout manager

from Tkinter import *

class Application(Frame):
    def __init__(self,master):
        Frame.__init__(self,master)
        self.grid()
        self.create_widgets()
    def create_widgets(self):
        #Instruction label
        self.inst_lbl = Label(self, text = "Enter password for the secret to longevity").grid(row = 0, column = 0, columnspan = 2, sticky = W)
        
        #Password label
        self.pwd_lbl = Label(self, text = "Password: ").grid(row = 1, column = 0, sticky = W)
        
        #Entry widget
        self.pw_ent = Entry(self).grid(row = 1, column = 1, sticky = W)
        
        #Submit button
        self.submit_bttn = Button(self, text = "Submit", command = self.reveal).grid(row = 2, column = 0, sticky = W)
        
        #Text box
        self.secret_txt = Text(self, width = 35, height = 5, wrap =WORD).grid(row = 3, column = 0, columnspan = 2, sticky = W)
    def reveal(self):
        contents = self.pw_ent.get() #This is where I get the error
        if contents == "secret":
            message = "Live to 99 then be really careful"
        else:
            message = "Incorrect password"
        self.secret_txt.delete(0.0,END)
        self.secret_txt.insert(0.0,message)
#main
root = Tk()
root.title("Longevity")
root.geometry("250x150")

app = Application(root)

root.mainloop()

File "/usr/lib/python2.5/lib-tk/Tkinter.py", line 1406, in __call__
return self.func(*args)
File "/home/chaos/none", line 27, in reveal
contente = self.pw_ent.get()
AttributeError: 'NoneType' object has no attribute 'get'