<!DOCTYPE html> <html style="height: 100%"> <head> <script> function doIt() { var d = document.createElement("div"); d.setAttribute("style", "position: absolute; left: 0; right: 0; top: 0; " + "bottom: 0; background: green"); document.getElementById("x").appendChild(d); } </script> </head> <body style="height: 100%" onload="doIt()"> <table style="height: 50%; width: 50%"> <tr> <td id="x" style="position: relative; top: 25%; left: 25%"> </td> </tr> </table> </body> </html>