global variable in tcl proc – fails when move the proc

We have a tcl proc that uses a global variable.  When it is used in the TPS Inbound Data location, it works fine.  When it is moved and used as a pre proc on a route, it errors because it doesn’t recognize the variable.  What is different about placing it in those 2 locations.  Here is the beginning of the TCL up to where it errors:

proc merge_A02 { args } {

   global A02_save A02_svmsg

   keylget args MODE mode                      ;# Fetch mode

   switch -exact — $mode {

       start {

           # Perform special init functions

           # N.B.: there may or may not be a MSGID key in args

           set A02_save 0;set A02_svmsg “”

           return “”

       }

       run {

           # ‘run’ mode always has a MSGID; fetch and process it

           keylget args MSGID mh

           set message [msgget $mh]

           set evn4 [ getField “$message” EVN 4 0]

           if { ![regexp {A02} $message] } {

               return “{CONTINUE $mh}”

           }

           if { [cequal $evn4 “SWAP”] } {

               if {$A02_save} {

And here is the error:

can’t read “A02_save”: no such variable

   while executing

“if {$A02_save} {

Thanks,

Kenadi Moore

OhioHealth