Close dialogbox after (vla-save $doc)

(vla-save doc) versus (Command "_SAVE" "")

 
(defun c:purgesave (/ $acad $doc i LayoutsLst nLayoutsLst)
 (vl-load-com)
 (setq $doc (vla-get-activedocument (vlax-get-acad-object)))
 (repeat 4
   (vla-purgeall $doc)
 )
 (setq i 0
LayoutsLst
 (layoutlist)
nLayoutsLst
 (length LayoutsLst)
 )
 (repeat (- nLayoutsLst 1)
   (command "_.LAYOUT" "_D" (nth i LayoutsLst))
   (setq i (1+ i))
 )
 (vla-save $doc)
 (vlax-release-object $doc)
 (princ
   "\nDrawing has been completely purged and successfully saved."
 )
 (princ)
)

Why you get after using the program PURGESAVE

at the CLOSE command a dialog box for saving in

some drawings.(See TestDwg

Is (vla-save $doc) something else than (Command "_.SAVE" "").

Regards.

TestDwg00.dwg