Adding comments into page from a form



I need to have a simple form with an input box for the person's name, email and the comment that will be posted. Here is a section I have found from this site that shows the actual script for the form (with slight changes):

<form action="do_comments.asp?level_id=1492" method="post">
<td class="main" valign="top">Your name (optional):</td>
<td class="main" valign="top"><input type="text" size="32" maxlength="24" name="str_posters_name" value=""></td>
<td class="main" valign="top">Comments? (required):</td>
<td class="main" valign="top"><textarea cols="32" rows="6" name="txt_comment" wrap="virtual"></textarea></td>
<td class="main" valign="top" align="center"><input type="submit" value="Post comment" id=submit1 name=submit1><br /><br /></td>

This is referring to this site:

There are certain things that I need explaining, such as the first line of the form:

<form action="do_comments.asp?level_id=1492" method="post">

Also, I need to know how to actually get this to be posted as comments as you can see at the bottom of the link. I think it needs something to do with a database, but I have no idea where to even start with something like this.

Any help would be greatly appreciated.
Very good point, I did not notice this was done in asp. I will need to do it in php if it is possible because my hosting does not support asp anyway. To see what I am trying to accomplish, here is a site that has the same kind of comments section, although this is done in asp: