Newbie has questions

[Newbie]

I'm new to web programming and have a couple questions.
Please excuse the novice nature of them:

1) How can I save my web pages as .html instead of .htm?

2) If the "index" file is save as .htm, it does not
automatically load, correct?

3) How can I prevent someone from reading the contents of
a directory? For example, if I have images at the
following address: www.abc.com/images, how doe I prevent
someone from typing www.abc.com/images and pulling up the
list of contents?

Thanks!!!!

 

[Tom Pepper Willett]

1) Right click on the page and change the extension.

2) Depends on what the host requires as the default page.

3) Make sure your host has disable directory browsing on your folders.