jQuery toggleClass example

Toggle class name on click in jQuery

HTML

<form id="form">
  <input name="one"/>
  <button>submitr</button>
</form>

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#banner-message {
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  font-size: 25px;
  text-align: center;
  transition: all 0.2s;
  margin: 0 auto;
  width: 300px;
}

button {
  background: #0084ff;
  border: none;
  border-radius: 5px;
  padding: 8px 14px;
  font-size: 15px;
  color: #fff;
}

#banner-message.alt {
  background: #0084ff;
  color: #fff;
  margin-top: 40px;
  width: 200px;
}

#banner-message.alt button {
  background: #fff;
  color: #000;
}

JavaScript

// find elements
const form = $("#form")

function Value() {
  let sum = 101;
  return sum; // you need a return
}

// handle click and add class
form.on("submit", (e) => {
  e.preventDefault();
  let one = $('input[name="one"]').val();
  let myValue = Value();
  $.post( "login.php", { value: myValue, one: one });
})