(defun c:abl(/ bset1 blng1 ba1 bl1 ba2 ba3 go1 bl2 ba5)
; Changes attributes to match the layer of the block

(command "undo" "group")

(prompt "\nSelect blocks with attributes to match layers: ")
 (setq bname (getstring "\nEnter block name to change: "))
  (setq bset1 (ssget "x" (list (cons 0 "INSERT")(cons 2 bname))))
(if (= bset1 nil)
(setq blng1 0)
(setq blng1 (sslength bset1))
)


(while (/= blng1 0)
(setq ba1 (entget (ssname bset1 0)))
(setq bl1 (assoc 8 ba1))
(setq ba2 (cdr (assoc -1 ba1)))
(setq ba3 ba1)
(setq go1 nil)
(while (/= go1 "stop")
(setq ba3 (entget (entnext (cdr (assoc -1 ba3)))))
(setq ba4 (assoc 0 ba3))
(cond
((equal ba4 (cons 0 "ATTRIB"))
(setq bl2 (assoc 8 ba3))
(setq ba5 (subst bl1 bl2 ba3))
(entmod ba5)
(entupd ba2)
(setq ba5 (subst (cons 62 0) (assoc 62 ba3) ba5))
(entmod ba5)
(entupd ba2)
)
((equal ba4 (cons 0 "SEQEND"))
(ssdel ba2 bset1)
(setq blng1 (1- blng1))
(setq go1 "stop")
)
)
)
)

(command "undo" "end")
(princ)

)