I have written this lisp to block out an area of a drawing and create a pdf. Unfortunately it chrashes in the file that it is trying to create is already present, Can anyone suggest a way to check for the variable fname prior to tyring to write the block, Also, Is it possible to write an error function into this lisp or does the fact that it jumps from one drawing to another mean that this is not possible. (Defun c:ext (/ nsheet dname dname1 dpref oldname fname pt1 ss1 echo) (setq ECHO (GETVAR "CMDECHO")) (SETVAR "CMDECHO" 0) (setvar "lispinit" 0) (setq sheetno (getstring " sheet number (if allready converted then delete old files) ?: ")) (setq dname (getvar "dwgname")) (setq dname1 (substr dname 1 (- (strlen dname) 4))) (setq dpref (getvar "dwgprefix")) (setq oldname (strcat dpref dname1)) (setq fname (strcat "C:/My Documents/PLOTFILES/" dname1 "-sched-" sheetno)) (setq pt1 (getpoint " pick left hand corner of sheet?: ")) (setq ss1 (ssget)) (command "sdi" "1") (command "-wblock" fname "" pt1 ss1 "") (command "undo" "1") (command "qsave") (command "fileopen" fname) (command "plot" "y" "" "pdf995" "a4" "m" "p" "n" "e" "f" "0,0" "y" "a3.ctb" "y" "n" "n" "n" "y" "") (command "fileopen" "y" oldname) (setvar "lispinit" 1) (command "sdi" "0") (SETVAR "CMDECHO" ECHO) (princ) ) Many thanks Spencer