js-slava

"use strict";

let login =['jon', 'max', 'henry','slava'];
let pass = 'i,'+ login[0,1,2,3];

let hello = prompt('who`s there ');

if (hello==login[0,1,2,3]) {
    let pin = prompt('input password ');
    if (pin==pass) {
        alert('hello ' + hello);
    }
    else if (pin==''||pin==null) {
        alert('error');
    }
    else{
        alert('undefinded');
    }
}

else if (hello==''||hello==null) {
    alert('error');
}
else{
    alert('undefinded');
}