Modify attribute

I want to change the value of an attribute, in a block with attributes
throught a autolisp routine
I tried the commands subst, entupd and entmod but the entity not didn't
change.
what wrong?

Dimitris

 

Post the code, but in the mean time, did you REGEN?

 

Thank you for answering
I tried and it works

This routine adds the string "N" to an attribute of selected blocks named
"ajonb"

Is the line (entupd blo) necessary ?
It seems to works with or without this command

;;;AL-AJONB.LSP
;;;
(defun c:al-ajonb ()
(setq oldecho (getvar "cmdecho"))
(setq oldlay (getvar "clayer"))
(setvar "cmdecho" 0)
(While
(setq blo(car(entsel "\Pick block for change..:")))
(if (or (= (cdr (assoc 2 (entget blo))) "ajonb")
(= (cdr (assoc 2 (entget blo))) "AJONB")
)
(progn
(entmod
(subst (cons 1 "N") (assoc 1 (entget(entnext(entnext blo))))
(entget(entnext(entnext blo))))
)
(entupd blo)
);;;end progn
);;;end if
);;;end while
(command "layer" "s" oldlay "")
(setvar "cmdecho" oldecho)
);;;end defun