(vl-load-com)
(if (null *save:react*)
   (setq *save:react* (vlr-command-reactor nil '((:vlr-commandwillstart . savedwg)))
         *save:acdoc* (vla-get-activedocument (vlax-get-acad-object))
         *save:count* 0
   )
)

(defun savedwg ( reactor params )
   (if
       (and
           (not (wcmatch (strcase (car params)) "*UNDO"))
           (zerop (rem (setq *save:count* (1+ *save:count*)) 10))
       )
       (if (zerop (getvar 'DWGTITLED))
           (vla-saveas *save:acdoc* (strcat (getvar 'DWGPREFIX) (getvar 'DWGNAME)))
           (vla-save   *save:acdoc*)
       )
   )
   (princ)
)
(princ)