require(tcltk)      # Load the tcltk package



tt <- tktoplevel()  # Create a new toplevel window

# Create a textbox 
OK.text <- tktext(tt, bg="white", height=20, width=80, wrap="none")
       
# Create a button whose function (command) is to destroy the window
OK.but <- tkbutton(tt, text = "OK", command = function() tkdestroy(tt))

# Place the textbox on the window, using the grid manager
tkgrid(OK.text)


# Place the button on the window, using the grid manager
tkgrid(OK.but)

# Now, bring the window to the focus, using tkfocus.  (This will not work
# if the code is run from Rgui, because the focus will automatically
# return to Rgui, but it will work if the code is copied and pasted into
# a script file and run using
# Rterm < scriptfile.R > scriptfile.Rout
tkfocus(tt)

print("Hello World ... is running")

tkmessageBox(message="Hello World", icon="error")