Thank you for your quick reply!!
With response to your reply our Network Ip ranges are all class c so conflict does happen if the user's router/modem at home also users the same class c range.
I was thinking about using
if (isInNet(myIpAddress, "192.168.subnet.0", "255.255.255.0")) ||
(isInNet(myIpAddress, "192.168.anothersubnet.0", "255.255.255.0")) ||
etc...
The only problem is that we have about 20 subnets, curious to whether it may lag checking all the ranges.
Will let you know