You want to play your DVD player into your laptop, correct? In this case, you'd need a capture card. There are a few options, either USB(which I don't suggest) then there's PC-Card(PCMCIA) capture devices. There's also firewire, and analog to firewire converters. It all really depends on what you wish to spend as all these could range from about $25 to around $300+.
If you meant output, some laptops have TV out, others require a converter. If you want such a device, I have one I've been trying to sell. Just shoot me a PM if so.