Do nothing or something

I’ve probably been searching in the wrong places but I can’t work out how, in an Obey file, to;

IfThere (an object) then (do nothing) else (do something)

It’s going to be simple, isn’t it (sigh)

IfThere (an object) Then Else (something)

Thank you. Didn’t think of omission. Service, eh!

With a smile!

Echo Nothing { > null: } ;-)