Insert HTML code in WYSIWYG field

Hi

I wonder whether it is possible to insert HTML (and PHP) code into a WYSIWYG field as it can be done in a Separator type of field.

My code is the following:

<?php
// Ensure error reporting to catch potential issues
error_reporting(E_ALL);
ini_set('display_errors', 1);

// Display the $RECORD array for debugging
//echo '<pre>';
//print_r($RECORD);
//echo '</pre>';

// Check if 'date_of_visit' exists and copy its value to a new variable
$dateOfVisit = isset($RECORD['date_of_visit']) ? htmlspecialchars($RECORD['date_of_visit']) : 'Ημερομηνία δεν είναι διαθέσιμη';
?>

request: <?php echo htmlencode(@$_REQUEST['date_of_visit']); ?>

<div>
<center>

<p>
Report
</p>
<div style="text-align: left;">
Athens
<?php
// Use the copied value
echo $dateOfVisit;
?>
</div>

<?php
// Display other fields
echo isset($RECORD['office']) ? htmlspecialchars($RECORD['office']) : 'Γραφείο δεν είναι διαθέσιμο';
echo ' / ';
echo isset($RECORD['type_of_visit']) ? htmlspecialchars($RECORD['type_of_visit']) : 'Τύπος επίσκεψης δεν είναι διαθέσιμος';
?>
</center>
</div>

Although the code's content is visible when inserted in the HTML block of a Separator type field, it produces a null when inserted into the WYSIWYG field as a default value. 

Regards, 

Andreas Lazaris