PHP MySQL find IP address (between) stored IP address ranges

Hi,

I am wondering how to code a PHP MySQL 'SQL' query to find the given IP address between 2 stored IP address ranges.

I am trying this:
$theIp  = 'xxx.xxx.xxx.xxx';
$result = mysqli_query($link,"SELECT * FROM `ipAddresses` WHERE `start` <= '$theIp' AND `end` >= '$theIp'") or die(mysql_error());

But it doesn't seem to be working correctly.  Should i store the IP data differently? Not in one field.

Thanks in advance!