Tryit Editor v1.4

<html> <head> <script type="text/javascript"> function setColSpan() { var x=document.getElementById('myTable').rows[0].cells; x[0].colSpan="2"; x[1].colSpan="6"; } </script> </head> <body> <table id="myTable" border="1"> <tr> <td colspan="4">cell 1</td> <td colspan="4">cell 2</td> </tr> <tr> <td>cell 3</td> <td>cell 4</td> <td>cell 5</td> <td>cell 6</td> <td>cell 7</td> <td>cell 8</td> <td>cell 9</td> <td>cell 10</td> </tr> </table> <form> <input type="button" onclick="setColSpan()" value="Change colspan"> </form> </body> </html> | Your Result:
Edit the code above and click to see the result. | W3Schools.com - Try it yourself