[mod_python] What is happening here ?

[Thu May 10 23:09:35 2001] [error] PythonHandler myscript: Traceback
(most recent call last):
[Thu May 10 23:09:35 2001] [error] PythonHandler myscript:   File
"/usr/lib/python2.0/site-packages/mod_python/apache.py", line 176, in
Dispatch
    module = import_module(module_name, _req)
[Thu May 10 23:09:35 2001] [error] PythonHandler myscript:   File
"/usr/lib/python2.0/site-packages/mod_python/apache.py", line 331, in
import_module
    f, p, d = imp.find_module(parts[i], path)
[Thu May 10 23:09:35 2001] [error] PythonHandler myscript: ImportError:
No module named myscript

I get this error when I try to run the following script.

from mod_python import apache

def handler(req):
    req.content_type = "text/plain"
    req.send_http_header()
    req.write("Hello World!")

    return apache.OK

Any help appreciated
David