Function to find filesize in KB,MB,GB

function ByteSize($bytes)
{
$size = $bytes / 1024;
if($size < 1024)
{
$size = number_format($size, 2);
$size .= ' KB';
}else {
if($size / 1024 < 1024) {
$size = number_format($size / 1024, 2);
$size .= ' MB';
} else if($size / 1024 / 1024 < 1024) {
$size = number_format($size / 1024 / 1024, 2);
$size .= ' GB';
}
}
return $size;
}