My code on website is not validate on W3 Validator.
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR...nsitional.dtd">
<html>
<head>
<title> Contact </title>
<meta name="description" content="Inzenjerski portal,baza znanja,vesti,seme,desavanja"/>
<meta name="keywords" content="Automatika,PLC,frekventni regulatori,arduino"/>
<meta name="author" content="Nikola Krga"/>
<meta name="robots" content="noindex, nofollow"/>
<link type="text/css" rel="stylesheet" href="about.css"/>
</head>
<body>
<table bgcolor="#b5a789" align="center" width="100%" border="1" cellpadding="10" cellspacing="6">
<tr>
<td bgcolor="#675c47" align="center"><font size="5" color="blue" >Contact</font></td>
</tr>
<tr>
<td align="center" bgcolor="efe5d0" >
<div id="nav">
<a href="projekat1.php" >HOME</a>
<a href="about.php" >ABOUT</a>
<a href="contact.php" >CONTACT</a>
</div>
</td>
</tr>
<tr class="main">
<td>
<ul type="circle">
<li><font color="blue" size="5">Arduino</font></li>
<li><font color="blue" size="5">tel:+38122656454</font></li>
<li><font color="blue" size="5">mob:+381642564829</font></li>
<li><font color="blue" size="5">e-mail:arduino@gmail.com</font></li>
</ul>
</td>
</tr>
<tr>
<td align="center" bgcolor="#675c47" width="100%" colspan="3">
© 2014, ARDUINO
<br/>
All trademarks and registered trademarks appearing on
this site are the property of their respective owners.
<br/><a href="http://validator.w3....">Validator</a>
</td>
</tr>
</table>
</body>
</html>