Replacing file images in background groups

[Ken Norris]

Howdy,

Still trying. Why doesn't this work (nothing happens)?

on mouseUp
  set the defaultFolder to "Doggies"
  set itemDel to "/"
  answer file empty with filter "JPEGs,*.jpg"
  lock screen
  delete image "bluescreen" in background "myImageGroup"
  create image (last item of it) in background "myImageGroup"
  unlock screen
  send "choose browse tool" to me in 20 milliseconds
end mouseUp

TIA,
Ken N.