How to insert a non-database field to table

Hello. I've got this kind of problem. I want to insert a non database field called "No" in to the first column of my table. I'm using server side script.

This is my array in server_processing.php file:

	$aColumns = array(' ' , 'surname', 'name', 'email', 'registration', 'activation' );

Retrieving data from database worked great until I added( ' ',) to $aColumns :(

This is my js:

$(document).ready(function() {
				$('#example').dataTable( {					
					"bProcessing": true,
					"bServerSide": true,
					"sAjaxSource": "server_processing.php",
				} );
			} );

This is my html:

<table cellpadding="0" cellspacing="0" border="0" class="display" id="example">
	<thead>
		<tr>
			<th>No</th>
                        <th>surname</th>
			<th>name</th>
			<th>email</th>
			<th>registration</th>
			<th>activation</th>
		</tr>
	</thead>
</table>

When i remove (' ',) from $aColumns and (<th>No</th>) from my html file everything works great.

Can you help me?:)
Sorry for my english:)

Greetings
Tom