How to write a code that every time a page loads, it update automatically a record field in mysql databse?

I have a table with counter as a INT field. Now I want to update this counter field with increment +1 everytime the page laods. Could anyone please help me?

make a file: functions.php

in functions.php write:

<?php
function counterAdd(){
$SQL="UPDATE yourTable SET counter=counter+1 (or counter++)";
$query=mysql_query($SQL) or die (mysql_error("update went bad");
}
?>

add this at page top:

<?
require_once('functions.php');
counterAdd();
?>