; try to find patient user wants to jump to and construct "AC" xref
LOCK(PSGPLG,APPL)
; Pick List routines use an ^XTMP node instead of locking, to allow some jobs to run concurrently on the same Pick List (PRINT and SEND TO ATC).
; PSGPLG=pick list number, APPL=option attempting to "lock", SETAPPL=option already in progress, APPLOK=if '1', option attempting to "lock" can proceed.