php table checkboxes doesn't work - php

Question

I have a table where I am displaying data from mysql. On the first column I have a checkbox. My php code is going to do something with the selected rows, but the problem is that my submit form doesn't work and i don't know why.
HTML code:
echo "<div class='container-fluid'>
<div class='table-responsive'>
<table class='fancyTable' id='myTable05'>
<thead>
<tr>
<th>Aviz</th>
<th>id</th>
<th>Denumire produs</th>
<th>Pret RON</th>
<th>U/M</th>
<th>Cantitate</th>
<th>Firma</th>
<th>Delegat</th>
<th>Mentiuni1</th>
<th>Mentiuni2</th>
<th>Cota TVA</th>
<th>Vsaloare</th>
<th>TVA</th>
<th>Facturat RON</th>
<th>Termen plata</th>
<th>Persoana contact</th>
<th>Pret ofertat</th>
<th>Reducere acordata</th>
<th>Nr comanda</th>
<th>Termen de livrare</th>
<th>Nr zile scadente ramase</th>
</tr></thead>";
while($row_comanda_afisare = mysqli_fetch_array($result_comanda_afisare)){
echo "<tbody><tr class='grid'>
<td>
<form action='includes/aviz.inc.php' method='post'>
<input type='checkbox' name='aviz_id[]' value='". $row_comanda_afisare['id']. "' />
</td>
<td>". $row_comanda_afisare['id']. "</td>";
echo "<td>". $row_comanda_afisare['denumire_produs']. "</td>";
echo "<td>". $row_comanda_afisare['pretRON']. "</td>";
echo "<td>". $row_comanda_afisare['U_M']. "</td>";
echo "<td>". $row_comanda_afisare['cantitate']. "</td>";
echo "<td>". $row_comanda_afisare['firma']. "</td>";
echo "<td>". $row_comanda_afisare['delegat']. "</td>";
echo "<td>". $row_comanda_afisare['mentiuni1']. "</td>";
echo "<td>". $row_comanda_afisare['mentiuni2']. "</td>";
echo "<td>". $row_comanda_afisare['cota_tva']. "</td>";
echo "<td>". $row_comanda_afisare['valoare']. "</td>";
echo "<td>". $row_comanda_afisare['tva']. "</td>";
echo "<td>". $row_comanda_afisare['facturatRON']. "</td>";
echo "<td>". $row_comanda_afisare['termen_plata']. "</td>";
echo "<td>". $row_comanda_afisare['persoana_contact']. "</td>";
echo "<td>". $row_comanda_afisare['pret_ofertat']. "</td>";
echo "<td>". $row_comanda_afisare['reducere']. "</td>";
echo "<td>". $row_comanda_afisare['nr_comanda']. "</td>";
echo "<td>". $row_comanda_afisare['termen_livrare']. "</td>";
//numarul de zile scadente
$sql_date = "SELECT DATEDIFF(termen_livrare, CURRENT_DATE) FROM comanda WHERE id=$row_comanda_afisare[id]";
$result_date = mysqli_query($conn, $sql_date);
while($row_date = mysqli_fetch_array($result_date)){
$zile_scadente = $row_date['DATEDIFF(termen_livrare, CURRENT_DATE)'];
}
echo '<td>'.$zile_scadente. '</td></tr>';
}
echo "<input type='submit' value='aviz'></form></tbody></table></div></div></div>";
?>
<script src="lib/jquery/jquery.min.js"></script>
<script src="js/jquery.fixedheadertable.js"></script>
<script>
$('#myTable05').fixedHeaderTable({
altClass: 'odd',
footer: true,
fixedColumns: 1,
});
</script>
</section>
The problem is that when i press on the submit button it is not taking me to the includes/aviz.inc.php file...does anyone know why?