Can you help?

I'm a newby. I have set up a sample page with the wizard. It works fine. I have copied and pasted this sample to my site (built in Golive CS2) to test it live. When I fill in the details and submit I get a page saying:
Method Not Allowed

The requested method POST is not allowed for the URL /index.html.

What am I doing wrong? I'm sure its simple. I just can't see how to intergrate the form into my page.

I hope you can help. Thanks in advance