Hi,
If it is only a dvd recorder rather than one with a hard drive what you need to do is record the first tape then press record pause rather than stop. Now record your second tape and so on. Once you have assembled all your film onto the disc press record stop. You will now have a rough version on the dvd.
Some dvd recorders will allow you to trim bits out of the middle (such as adverts) before finalising the disc. You will need to check your manual to see if this is possible or tell us the model of your Panasonic dvd recorder, the info will be out there on the web somewhere.