Python Tk - please install the python-tk package

I got error message: please install the python-tk package

I googled the error message and found this:

http://ubuntuforums.org/showthread.php?t=655307

The instruction there gave me a hint of what to do.
I opened System -> Administration -> Synaptic Package Manager -> Settings
then I found   Python Programming language in the window there ... and highlighted "Python Programming language" and clicked on python-tk and finally got the tool to install it.