for file upload to take place, the forms encoding type needs to be set to multipart/form-data.
change:
<form action="listing_Insert.php" method="post" name="WADAInsertForm" id="WADAInsertForm">
to:
<form action="listing_Insert.php" method="post" name="WADAInsertForm" id="WADAInsertForm" enctype="multipart/form-data">