Question

This part of the code is fine i do not see any problem there but still i can not insert it to the data base the following message appears.

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘check (quantity) VALUES (‘2′)’ at line 1

<?php
     if(isset($_POST['submit'])){
          $checkBox = $_POST['mycheck_box'];    
          for($i=0; $i< sizeof($checkBox); $i++){    
          echo $query = "INSERT INTO check (quantity) VALUES ('".$checkBox[$i]."')";
          echo "<br/>";
                        mysql_query($query) or die(mysql_error());
          }
       }
    ?>

Answer 1

Try

$query = "INSERT INTO `check` (quantity) VALUES ('".$checkBox[$i]."')";

CHECK is a MySQL keyword when creating tables.

On a side note, you should be filtering any $_POST values you receive from a form before doing anything with a database.