Untitled

function submit(params) {
  const firstName = document.getElementById('first-name').value;
  const lastName = document.getElementById('last-name').value;
  const username = document.getElementById('username').value;
  const email = document.getElementById('email').value;
  const contact = document.getElementById('contact').value;
  const postalCode = document.getElementById('postal-code').value;
  if (!/^[A-Za-z]+$/.test(firstName)) {
    window.alert('Enter valid first name!');
  } else if (!/^[A-Za-z]+$/.test(lastName)) {
    window.alert('Enter valid last name!');
  } else if (!/^[a-zA-Z0-9_]+$/.test(username)) {
    window.alert('Enter valid username!');
  } else if (!/^\w+@[a-zA-Z_]+?\.[a-zA-Z]{2,3}$/.test(email)) {
    window.alert('Enter valid email!');
  } else if (!/^[0-9]{10}$/.test(contact)) {
    window.alert('Enter valid contact!');
  } else if (!/^[0-9]{6}$/.test(postalCode)) {
    window.alert('Enter valid postal code!');
  } else window.alert('Submitted');
}