PHP: best Page Load Time script?

[Question Everything!]

What is the most accurate and reliable php script that displays the time it took for the page to load?
One that can be placed at the top only?

 

[glynn.alexander]

put this code at the very top of your webpage

<?
$time = microtime();
$time = explode(' ', $time);
$time = $time[1] + $time[0];
$start = $time;
?>

and this at the very bottom

<?
$time = microtime();
$time = explode(' ', $time);
$time = $time[1] + $time[0];
$finish = $time;
$total_time = round(($finish - $start), 4);
echo '<p>Page generated in '.$total_time.' seconds.</p>'."\n";
?>

this is how it will look

Page generated in 0.0031 seconds