DVDs are manufactured to play only in certain regions of the world. They carry "region codes" that specify the type of DVD player in which they will work. You can change your Philips DVD Player yourself by using hacks, or special command sequences from the remote control to switch regions or make the player play all discs.
Go to http://www.DVDdemystifiziert.de/codefree_en/philips.html and hit Ctrl + F on your keyboard to open up a search box.
Type in the model number of your DVD player, and you will be lead to a hack for it.
Follow the steps listed with your remote control and your DVD player will be unlocked.
If a hack for your model is not available on the aforementioned website, try searching for your model at http://www.videohelp.com/DVDhacks. If that does not work, it is still possible to unlock the DVD player. Some players can be physically modified to play discs from all regions.
Physically modifying the DVD player will often void the warranty on the machine and costs money. If you choose to do so, it is at your own risk. Likewise, using hacks to unlock your DVD player may not always work and it could cause damage to your machine.