If you have no HDMI on TV and DVD player, you have no choice but to use a triple scart cable ... or a scart switcher. You should get an auto switch one that will feed through to TV when you power up the device you want to use.
Also make sure it supports RGB connections and use that too if TV supports it .. the picture quality will be better.
http://www.ebay.co.uk...nkw=auto+scart+switch
Same as some ebay items twice the price ..
http://www.tlc-direct.../Products/MX520R.html
Don't buy Commtron (crap) or a cheap manual one.