Rows 6-17 & the front loop only

Here's what you need to do to crochet the rest of the briefcase:

Row 6: 8 sc flo, ch 1 and turn (8)
Row 7: 8 sc, ch 1 and turn (8)
Row 8: 8 sc flo, ch 1 and turn (8)
Rows 9-16: 8 sc, ch 1 and turn (8)
Row 17: 8 sc (8)

What's this? Another new abbreviation? flo means, you guessed it, "front loop only." With the right side of your work still facing out, insert the hook under the side of the horizontal V that's closer to you:

hook under front loop only 

Crochet each stitch like you normally would. You'll know you've done it correctly because there'll be a ridge on the other side of your piece:

ridge of remaining back loops

To finish, fasten off: