Basic JavaScript - Concatenating Strings with the Plus Equals Operator

hello guys my code doesnt pass

var myStr = “This is the first sentence.”;

mystr +=" This is the second sentence.";

console.log(mystr);

Hello and wellcome.

Rewiew your variables. Be care with uppercase and lowercase.

Grets.

The previous reply is correct. Just to add a bit to that, it appears the process may be missing a space after the first sentence. That was an issue I had to find with my own. Good luck.