I'm trying to send an alert window after the user successfully sends the email but it's not showing up. I've tried using both cookies and ajax success:, but neither strategy has worked. It sends the email successfully to the server, but the window just refreshes and no actual alert window pops up to alert the user that the email was sent. The code below is the javascript function that is in charge of sending the email.

function validateForm() {
  if ($('input[name=name]').val() !== "" || $('input[name=email]').val() !== "" || $('input[name=subject]').val() !== "" || $('textarea[name=message]').val() !== "") {
    formData = {
      'name': $('input[name=name]').val(),
      'email': $('input[name=email]').val(),
      'phone': $('input[name=phone]').val(),
      'subject': $('input[name=subject]').val(),
      'message': $('textarea[name=message]').val()
    };
    $.ajax({
      url: "../mail.php",
      type: "POST",
      data: formData,
      success: function(response) {
        alert(response.success);
      }
    });
  }
}