How to change data in a mySQl database ?

[bccron]

Hi!
Can anyone give me the ansver in how to change the data in my database from a html-page. Lets say I have the value of 10 in my database, and in my HTML-page I insert the value of 2, then I want the database value to be 8.

I use this code to insert data to my database (but I want to know how to withdraw) :

<?PHP

if ( isset( $number ) )
{
$query = "UPDATE count set antal = '$number'";
$result = mysql_query( $query );
if ( ! $result )
die ("can not update: ".mysql_error());
print "Updated with $number ". mysql_affected_rows() .
" row(s) changed</p>";
}

?>

Thanks...

[cdhogan]

you could use a query like:

update count set antal = antal - $number

[bccron]

Thanks it worked great and right away!