How can I get my dog to stop running out the door?

Our dog Kevin ran out the door today and it took about 1 to ½ hours to get him back. My great grand parents opened the door to a package and Kevin ran past them and ran faster then a thief on the run. luckily he is fine just tired. Is there anyone who knows how to get Kevin able to stop running out the door? Oh and no matter how hard we train him my grandpa somehow untrains him.