I have many required textboxes on my form. Each textbox has a label to the left of them. Next to the label, I have a red icon that I want to change to a green icon when its corresponding textbox is changed. The below code is not working. Can someone show me how I would do this?

2. // CSS
4. .required
5. {
6. background: #ffffff url(dot_red.png) no-repeat 0 0;
7. padding-left: 20px;
8. }
9. 
   
10. .filled
11. {
12. background: #ffffff url(dot_grn.png) no-repeat 0 0;
13. padding-left: 20px;
14. }
16. // jQuery
17. $(function () {
18. $(".required").change(function () {
19. if ($(this).val().length > 0) {
20. $(this).addClass("filled");
21. }
22. else {
23. $(this).removeClass("filled");
24. }
25. });
26. });