VLOOKUP multiple results in a drop down list

Attached is the file - what i would like is instead of just a blank cell a comment saying "NO NOTES FOR THIS CUSTOMER"

Ideally i would like it to default to that..... if there are no notes associated.

Else maybe a comment saying "DROP DOWN FOR NOTES ON THIS CUSTOMER"

So it will be one or the other... either NO NOTES or DROP DOWN FOR NOTES depending if there are notes or not..

hope that makes sense... all else is working at the moment...

Thanks very much.