<?php
   header("Content-Disposition: attachment; filename=test.xls"); 
   header("Content-Type: application/vnd.ms-excel");
   print "<table border=\"1\"><tr><td><b>field1</b></td><td><b>field2</b></td></tr>";
   print "<tr><td>value1 </td><td bgcolor=\"#137799\">value2 in blue cell bakground</td></tr></table>";
?>