invalid left-hand side in assignment when changing value of cell

https://support.smartbear.com/testcomplete/docs/reference/language/javascript/set-method.html

Its suppose to be a $. What is interesting is that when I try to use the %, it autocompletes, but gives me a syntax error right after, I also can't seem to be able to recreate it autocompleting. I realize I did not mention it before, apologies for that but we're using javascript for this project.