I tested mainpage:

Line 31, column 84: there is no attribute "border" (explain...).

...f="http://www.thebestisp.net" border="0">
^
Line 102, column 70: value of attribute "method" cannot be "POST"; must be one of "get", "post" (explain...).

...name="LsLogin" action="/index.php" method="POST">
^
Line 165, column 32: there is no attribute "language" (explain...).

script language="JavaScript"
^
Line 165, column 44: required attribute "type" not specified (explain...).

script language="JavaScript"



EDIT: I tested all the main-sections and it was the same misses on all of them

(I removed "" at javascript cuse it didnt show )