<!DOCTYPE html> <html> <head> <script language="javascript"> function toggleRow(rowId) { var r = document.getElementById(rowId); if (r.style.display == "none") r.style.display = "inline"; else r.style.display = "none"; } function doTest() { toggleRow('row4'); document.body.offsetWidth; toggleRow('row4'); document.body.offsetWidth; toggleRow('row4'); document.body.offsetWidth; toggleRow('row4'); document.body.offsetWidth; toggleRow('row4'); document.body.offsetWidth; toggleRow('row4'); document.body.offsetWidth; toggleRow('row4'); document.body.offsetWidth; toggleRow('row4'); document.body.offsetWidth; toggleRow('row4'); } </script> </head> <body onload="doTest()"> <table border="5"> <tr> <td>Row 1</td> </tr> <tr> <td>Row 2</td> </tr> <tr> <td>Row 3</td> </tr> <tr id="row4" style="display: none"> <td>Row 4</td> </tr> </table> </body> </html>