functionValidation

function validateEmail(email) {
  // Regular expression to match a valid email address
  const regex = /^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*$/;

  // If the email address does not match the regular expression, return false
  if (!regex.test(email)) {
    return false;
  }

  // Otherwise, the email address is valid, so return true
  return true;
}

// On change of the email input field, call the validateEmail() function
document.getElementById("email").addEventListener("change", function() {
  const email = document.getElementById("email").value;
  const isValid = validateEmail(email);

  // If the email address is invalid, display an error message
  if (!isValid) {
    document.getElementById("emailError").innerHTML = "Invalid email address";
  } else {
    document.getElementById("emailError").innerHTML = "";
  }
});