if else in thymeleaf

How to set if the variable not null, textView not editable, otherwise editable ?

 <p th:if="${users.name!=null}">
                <input type="text" input readonly="readonly" class="form-control" id="name" th:field="${username}" />
            </div></th:if></p>

Above code works if name not equal to null. How to make it editable if name is null?