private function _convertToNumber($nSize)
{
$_nReturn = substr($nSize, 0, -1);
switch (strtoupper(substr($nSize, -1))) {
case 'P':
$_nReturn *= 1024;
case 'T':
$_nReturn *= 1024;
case 'G':
$_nReturn *= 1024;
case 'M':
$_nReturn *= 1024;
case 'K':
$_nReturn *= 1024;
}
return $_nReturn;
}