Print all drawings within a file

I have made this lisp to select all the title blocks within a file and print. Title blocks are on different paper spaces.

What I did was (ssget "x" BlockName), check block's layout name, if layout name is not current, switch to that layout and print.

It works fine if the file is not very complicated (i.e. doesn't take too long to regen), but when the drawing is big enough, it takes time to regen when switching layouts, it ends up printing a blank paper in certain layouts, looks like to me is that the print command has executed before the drawing has finished regen. I though may be I should apply (pause) into my lisp but I have no idea how it works. Can someone please help.

Thank you

 
(foreach blks (layoutlist)
(setvar 'Ctab blks)
  (ssget "x" (list '(0 . "INSERT")(cons 2 blockname)(cons 410 (getvar 'Ctab))))
  (process before proceedign to next layout)
 )

Right...why didn't I think of this !!!! Thanks a lot