I found the problem, and have fixed it.
From line 30 to 46 in the CodeShareData.class.php file replace the code with the following:
public function save_new_codeshare($schedid, $airline, $image)
{
$query = "INSERT INTO phpvms_codeshares (schedid, airline, image)
VALUES ('$schedid', '$airline', '$image')";
DB::query($query);
}
public function save_edit_codeshare($schedid, $airline, $image, $id)
{
$query = "UPDATE phpvms_codeshares SET
schedid='$schedid',
airline='$airline',
image= '$image',
WHERE id='$id'";
DB::query($query);
}