You have a syntax error.
You want it to say, "use strict" not "user strict".
You also want to put "use strict" at the top of your file.
I've attached what I think you should change your code to.
"use strict";
function validateFields() {
var nameserverone = document.getElementById("ns1").value;
var nameservertwo = document.getElementById("ns2").value;
if (nameserverone === null) {
console.log("say Hi");
return nameserverone;
}
else {
console.log("Say Bye");
}
}
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