<p>I need to create a login form for a random user and when the password is incorrect the password box needs to turn red (border-color) and when the password is correct it needs to turn green. Can you help me with the Javascript code? If I make any mistakes, please forgive my English. Thanks. </p> <p>I tried this but the color didn't change. </p> <p> <pre class="brush:js;toolbar:false;">var users = [{ username: 'new_user', password: "123456789", }] function login(email, password) { var email = document.getElementById("email").value var password = document.getElementById("password").value for (var user of users) { if ((email === user.email || email === user.username) && password === user.password) { var block = document.querySelector('.nav'); block.style.display = "block" var errMsg = document.querySelector('.loginForm .errorMessage') errMsg.style.display = "none" var form = document.querySelector('.loginForm') form.style.display = "none" var name = document.getElementById("user-name") name.innerHTML = user.name; loggedUser = user; clearValue("email"); clearValue("password") } else { var errMsg = document.querySelector('.loginForm .errorMessage') errMsg.style.display = "block" var passwordBox = document.querySelector(".loginForm input.password") passwordBox.style.border.color = "red" } } }</pre> <pre class="brush:html;toolbar:false;"><div id="loginForm" class="loginForm"> <h1>Log in</h1> <input id="email" type="text" class="email" placeholder="email or username"> <input onkeyup="loginOnEnter(event)" id="password" type="password" class="password" placeholder="password"> <p class="errorMessage">*Please enter a valid password</p> <button onclick="login()" class="login-btn">Login</button> </div></pre> </p>