problem with Tkinter after installing Python 2.5.2 on UBUNTU

[Dogzilla1000 at gmail.com]

I just installed Python 2.5.2 on UBUNTU Linux. It seems to work,
however I don't seem to have access Tkinter. This is the result of
"import Tkinter":

Python 2.5.2 (r252:60911, Jul  7 2008, 12:39:49)
[GCC 4.2.3 (Ubuntu 4.2.3-2ubuntu7)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import Tkinter
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.5/lib-tk/Tkinter.py", line 38, in
<module>
    import _tkinter # If this fails your Python may not be configured
for Tk
ImportError: No module named _tkinter
>>>

What do I need to do to configure Python for Tk?