Simple GUI Demo in Python

from Tkinter import*
mainForm=Tk()

lblWelcome = Label(mainForm, text="Welcome to SSEBB Model")
lblWelcome.pack()

lblDisplay=Listbox(mainForm)

txtMyval=Entry(mainForm)
txtMyval.focus_set()
txtMyval.pack()

btnQuit=Button(mainForm,text="Close",command=quit)
btnQuit.pack(side="left",padx=10,pady=10)

def ShowVal():
lblDisplay.insert(0,txtMyval.get())


btnStart=Button(mainForm,text="Show in list",command=ShowVal)
btnStart.pack()

lblDisplay.pack(padx=20,pady=10)

mainForm.mainloop()

Python