form.html

<form id="leadForm" action="https://script.google.com/macros/s/AKfycbyd9b-t6PKBKZPrtKTNhG9fNUWHmPGjVg4VnhWIrKundTFlZLI/exec">
    <input type="email" name="email" placeholder="Your email address">
    <input  type="submit" id="LeadFormSubmit">
</form>

<script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>

<script type="text/javascript">
    $(document).ready(function(){
        var $form = $('#leadForm');
        var $subm = $('#LeadFormSubmit');
        var $impt = $form.find(':input').not(':button, :submit, :reset, :hidden');
        $form.submit(function(){
            $.post($(this).attr('action'), $(this).serialize(), function(response){
                $impt.val('').attr('value','').removeAttr('checked').removeAttr('selected');
                $subm.prop('disabled', true);
            },'json');
            return false;
        });
    });
</script>