too long

I want two <option> output form database by while loop and also need to receive it form $_POST[''] function but i am getting only one <option> output. double <option> not appears form these codes. what wrong i am doing here?

$q6 = mysql_query("SELECT * FROM menu");
echo '<form action="" method="post">'.'Need To Change <select name="tobechanged">';
while ($row = mysql_fetch_array($q6)) {
    $menu_name = $row['menu_name'];
    echo '<option value="'.$menu_name.'">'.$menu_name.'</option>';

}
while ($row = mysql_fetch_array($q6)) {
    $menu_name2 = $row['menu_name'];
    echo '<option value="'.$menu_name2.'">'.$menu_name2.'</option>';

}

echo '</select><br>
  <input type="submit" name="pchange_submit" value="Change it">
</form>';

if (isset($_POST['pchange_submit'])) {
    echo $_POST['tobechanged'];
}

    $q6 = mysql_query("SELECT * FROM menu");
echo '<form action="" method="post">'.'Need To Change <select name="tobechanged">';
while ($row = mysql_fetch_array($q6)) {
    $menu_name = $row['menu_name'];
    echo '<option value="'.$menu_name.'">'.$menu_name.'</option>';

}

echo '</select><br>
  <input type="submit" name="pchange_submit" value="Change it">
</form>';

if (isset($_POST['pchange_submit'])) {
    echo $_POST['tobechanged'];
}