Modify these lines:
echo "<form id='forma1' action='' method='POST'>";
while($row2=mysql_fetch_row($result2)) {
echo "<input type='checkbox' name='kolona[]' value='{$row2[0]}' />{$row2[0]}</br>";
}
echo "<input type='submit' name='submit' value='{$tablename}'/></form>";
echo "</div>";