Change the width of a table border
<html> <head> <script type="text/javascript"> function changeBorder(){ document.getElementById('myTable').border="20" } </script> </head> <body> <table border="1" id="myTable"> <tr> <td>a</td> <td>b</td> </tr> <tr> <td>c</td> <td>d</td> </tr> </table> <form> <input type="button" onclick="changeBorder()" value="Change Border"> </form> </body> </html>