This if-then-else consistently conditioning on one variable, and consistently assigning it to another variable works fine. Another way to do it is a switch statement, which has it's pitfalls. Another way that I think doesn't get as much attention is to create a map of newControlValue -> controlIdValue
map = {zoom:'nwc-zoom', pan:'nwc-navigation'}

you can then say
var controlId = map[newControl] || 'defaultValue';

Your approach is fine since there's so few values in this case; I just wanted to give some food-for-thought.