Or do what we did here...tacked down one side of the "flap", build a box under the area where the sewing machine would go and add a piano hinge to the other "flap". Makes for an awesome vanity!
See what is underneath the glass I put on top! A big ol' hold! But who cares! With this beautiful sheet of metallic glass on top you would never know! And check out the nice, deep drawers on this piece.