When an elder enters the room:

Stand to acknowledge them and welcome them. If you know them, shake their hand and tell them how nice it is to see them again. If you don't know them, stand and wait to be introduced. Once you are introduced, shake their hand if they offer theirs. Always stop what you are doing and show respect to those in the room even when you or they are just passing through. Listen to them when they speak. Contemplate what they say. Consider them when they speak and never interrupt them. These people have been around a long time, and could still out live you. So listen to what they say if you too want to live a long time and be treated with respect.  And don't give me the "I only respect those that respect me" crap. That don't work.  I agree some elders aren't worth respecting, but unless you know them intimately, never be the one that demands respect first before an elder. I remember being required to stand whenever a teacher or the principal entered the room.  Don't they do that anymore?