<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <script> function boom() { var td = document.createElementNS("http://www.w3.org/1999/xhtml", "td"); td.appendChild(document.createTextNode("b")); document.getElementById("tbody").appendChild(td); } </script> </head> <body> <table border> <tbody id="tbody"> <tr> <td rowspan="0">a</td> </tr> <tr> </tr> </tbody> </table> <script> // Flush layout document.body.offsetWidth; boom(); </script> </body> </html>