I'm learning jquery. I'm trying to display error messages when form validation fails.

Currently the error message does show but disappears straight away. I am doing this in wordpress, trying to create my own validation plugin.

It does show the error message 'This field cannot be empty' when I click submit but disappears straight away.

The below code is in the sks_email_form.php file

2. function jquery_validation(){
3. //echo 'Inside jquery_validation'; //works
4. //echo plugins_url('/js/validation2.js', __FILE__); // correct 
5. if(!is_admin()){
6. ?><script type="text/javascript" src="<?=plugins_url();?>/Sks_email_form_plugin/js/validation2.js"></script>
7. <script type="text/javascript">
8. var $j = jQuery.noConflict();
9. $j(document).ready(function(){
10. $j('#sks_email_form').submit(function(){
11. validation();
12. });
13. });
14. </script>
15. <?}
16. }
17. function sks_email_form(){
18. echo "<form name='sks_email_form' id='sks_email_form' method='post' action=''>
19. <table class='email_table'>
20. <tr>
21. <td>
22. Full name:
23. </td>  
24. <td>
25. <input type='text' name='fullname' id='fullname'/>
26. </td>
27. </tr>
28. <tr>
29. <td id='full_name_err_msg'>
30. </td>
31. </tr>
32. <tr>
33. <td>
34. Email:
35. </td>
36. <td>
37. <input type='text' name='email' id='email'/>
38. </td>
39. </tr>
40. <tr>
41. <td>
42. Message:
43. </td>
44. <td>
45. <textarea name='msg' id='msg' cols='35' rows='6'></textarea>
46. </td>
47. </tr>
48. <td>
49. <input type='submit' name='submit' id= 'submit' value='Submit'/>
50. </td>
51. <td>
52. <input type='reset' name='reset' value='Reset'/>
53. </td>
54. </tr>
55. </table>
56. </form>";
58. }

In javascript file I have the following:

2. var $j = jQuery.noConflict();
4. (function($j){
5. validation = function(){
6. var full_name = $j('#fullname');
7. var full_name_err_msg = $j('#full_name_err_msg');
9. //alert('full_name: '+full_name.val()); // works
10. is_field_empty(full_name, full_name_err_msg);
11. }
12. function is_field_empty(elem, elem_err_msg){
13. //alert('inside is_field_empty function'); // works
14. if(elem.val()==""){
15. elem_err_msg.css('border', 'red solid 1px');
16. elem_err_msg.html('This field cannot be empty');
17. }
18. }
19. })(jQuery);
20. 
    

Can anyone please tell me what I am doing wrong? 

Thanks

Alucard007