#3018: tkinter demo fixes for py3k.
diff --git a/Demo/tkinter/guido/electrons.py b/Demo/tkinter/guido/electrons.py
index 6079c04..896e079 100755
--- a/Demo/tkinter/guido/electrons.py
+++ b/Demo/tkinter/guido/electrons.py
@@ -62,11 +62,11 @@
 
 # Main program
 def main():
-    import sys, string
+    import sys
 
     # First argument is number of electrons, default 30
     if sys.argv[1:]:
-        n = string.atoi(sys.argv[1])
+        n = int(sys.argv[1])
     else:
         n = 30