PHP,CSS,JQUERY,HTML tips for beginners

//for user section view


<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td>
<textarea name="newsletterContent" rows="50" cols="100" style="border:1px solid #a2a2a2;">
<?php if(strstr(html_entity_decode($thisDataPaket['NewsletterContent']), "-->"))
{
echo substr(html_entity_decode($thisDataPaket['NewsletterContent']), strrpos(html_entity_decode($thisDataPaket['NewsletterContent']), "-->")+3);
}
else
{
echo html_entity_decode($thisDataPaket['NewsletterContent']);
}
?>
</textarea>
</td>
<td><?php if($newsletterContenttError) {?><span style='color:red;'>*</span> <?php } else { ?> <span style='color:black;'>*</span><?php } ?></td>
</tr>
</table>


//For insert tinymce data

$newsletterContent = "";
if(!empty($_REQUEST['newsletterContent'])) $newsletterContent = $_REQUEST["newsletterContent"];

if($_REQUEST['newsletterContent'] != "")
{
if(get_magic_quotes_gpc())
{
$newsletterContent = stripslashes($_REQUEST['newsletterContent']);
}
}
$newsletterContent = htmlspecialchars($_REQUEST['newsletterContent']);
$newsletterContent = str_replace("'", "\'", $newsletterContent);