I'm just trying to learn to basics to java script but I'm very confused on which I'm sure is a simple question. Just need a quick answer to what I'm doing wrong. Thank you.
The first thing issue I can see here is that seeing two commas there,
it's showing firstname,,lastname (you can see it in the error message),
when in fact, its firstname,lastname.
Try removing the one comma you see in the editor.
Hope this helped,
If you need any more js help feel free to PM me.
The bug was in line 8 which you seemed to resolve (the extra comma). If you pressed "Run Code" again and the error didn't go away, the site is probably bugged.