Without a doctype, you are in quirks mode, not standards mode. All new pages are required to have a doctype.
Also, you are using xhtml end tags but quirks mode is html only. There are html errors, too.
ok, just tell me, should I convert the table layout into div for such a light weight page or I should let it be like that?
Also I modified it and now according to w3validator, it has only two errors.
1. there is no attribute "height".
<table width="100%" height="100%">
2. there is no attribute "name".
<form name="F" action="/index.php" method="post">
What can I do with this now?