Script file hangs following insert command

I'm running a script file ".scr" that will add a watermark "DRAWING REVISED" to thousands of obsolete drawings. The script file hangs after the value 0 in the insert command. The program will continue if I enter RESUME in the command line. I've tried, blank lines, 'Resume, other combinations to no avail. I using the cal command (which seems to be the problem) to scale the inserted block as the drawings are all different. Any help would be appreciated.

 
OPEN c:\dwgsRevised\32402085S00R01.DWG
ZOOM E
cal
p2=getvar(extmax)
cal
p1=getvar(extmin)
INSERT c:\dwgsRevised\dwgrevised 'cal
p2
'cal
round((abs(p2-p1))/15)
'cal
round((abs(p2-p1))/15) 
'cal
0
RESUME
ZOOM E
SAVEAS  c:\dwgsRevised\32402085S00R01.DWG
close