Reading the last five entries in database from bottom to top

I have a database called main_news with three fields: Subject, Text and an auto-incrementing field called newsid.

I want to read out the last five news posts from bottom to top, so if i post something it comes out first and the other 4 below it. I want the subject to come out first and in bold, then a <br> and then the text of the news, then a <br> then the next subject etc.

I have been stuck on figuring out how exactly to do this.. any help is appreciated, thanks in advance.

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /home/ecliptic/public_html/index.php on line 34

i get that when i use your code
while($result=mysql_fetch_array($do)) {
print "<b>".$row["subject"]."</b><br>";
print $row["text"]."<br>";
}

Oh, right woops messed up my variable names this'll work:

I changed the $do to $result and im still getting the same error

I noticed another error in the code, try this...

<?php
$conn=mysql_connect("localhost","","");
mysql_select_db("",$conn);
$result=mysql_query("select * from main_news order by newsid desc limit 0,5");
while($row=mysql_fetch_array($result)) {
print "<b>".$row["subject"]."</b><br>";
print $row["text"]."<br>";
}
mysql_close($conn);
?>

Changed the variable $result to $row in the while statement. Seems to work for me