Yes, You will need to use different IDs for each layout. If You are just doing a couple this might be the easiest route to go. However you will quickly reach the point you will want to use "class" as an identifier.
Do a search for "Class" on the Forum. I would not make it more specific than this as what You may find useful for your purposes - including learning about the use of "classes" in general - may be missed with a finer sieve.
Here is a thread that may be most pertinent to your current need - if You go the "class" route. At the minimum it would be a good starting point for further research.