;****Secilen bloklari yenileriyle degistirir..****

(defun c:bc (/ on nn ss ad ms i ob) (vl-load-com)
  (defun *error* (msg)
    (if (not (wcmatch (strcase msg t) "*break,*cancel*,*exit*"))
      (princ (strcat "\nError: " msg)) (princ)))
  (if (/= (setq on (getstring T "\nOld block name:")) "")
   (if (/= (setq nn (getstring T "\nNew block name:")) "")
    (if (setq ss (ssget (list (cons 0 "insert") (cons 2 on))))
     (progn
       (setq ad (vla-get-activedocument (vlax-get-acad-object))
             ms (vla-get-modelspace ad) i -1)
      (vla-startundomark ad)
       (while (< (setq i (1+ i)) (sslength ss))
        (setq ob (vlax-ename->vla-object (ssname ss i))
              obi (vlax-safearray->list
                (vlax-variant-value (vla-get-InsertionPoint ob))))
        (vla-delete ob) (vla-InsertBlock ms (vlax-3d-point obi) nn 1 1 1 0)
       )
      (vla-endundomark ad)
     )
    )
   )
  ) (princ)
)