Warning: do not use Seppili's function to floor with decimals. It will lead you to a lot of trouble because of float number precision.
For example floordec(0.29, 2) will result in 0.28.
Here's a little fix that will help you get around some problems:
<?php
function floordec($value,$decimals=2){
return floor($value*pow(10,$decimals)+0.5)/pow(10,$decimals);
}
?>