thank you you're quick!

this is the form that shows up under my blog

<form name="add_comments" action="<?php echo $_SERVER['PHP_SELF'];?>" method="POST">
<input name="user" type="text" \><br \>
<input name="email" type="text" \><br \>
<textarea name="comment"></textarea>
</form>

this is what he gave me to put the form into my database

insert into comments (name, email, comment) values ( $name, $email, $comments)

That's a start. 

Add this after the textarea and before the end of the form:

<input type="submit" \>

That will give you the button to submit the comment.

As for adding the form data to the database, it looks like your friend didn't give you all the code you need.  Try this on for size:

$db_link = mysql_connect( "your_mysql_host", "mysql_user", "mysql_password" );

That will get you connected.  Then, you'll need to pull the form data from the $_POST variable:

$user = $_POST['user'];
$email = $_POST['email'];
$comment = $_POST['comment'];

Then, add that to the database with this:

mysql_query("INSERT INTO comments (name, email, comment) VALUES ($user, $email, $comment);

That will post the data into your database as you expected.  Hope that helps!