A function that calculates the running time of a php page

/*
Calculate php program running time
*/
function microtime_float()
{
list($usec, $sec) = explode(" ", microtime( ));
return ((float)$usec + (float)$sec);
}
//Start timing and put it on the head
$starttime = microtime_float();
/ /End the timer and put it at the bottom
$runtime = number_format((microtime_float() – $starttime), 4).'s';
//Output
echo 'RunTime:'.$runtime;
?>< /p>