The entity type doesn't have an 'id' member by default. What it does have is a set of skills that you can set your own custom id...

me.skill1 = 50;

... So when checking ids you can easily check the entity skill.

The skill method would require you to manually set the ids. You can use the handle of the entity also. A handle is a number unique to the object which is automatically set by the engine.

Use the 'handle' function (check in manual) or directly access it with 'my.link.index'.