PACKET openDEFINES openwork,closework,workopened,workclosed,initcheckrerun,
checkrerun,hdversion:BOOL VAR open;INT VAR oldsession;BOOL VAR hdflag:=FALSE 
;INITFLAG VAR packet:=FALSE ;PROC openwork:open:=TRUE END PROC openwork;PROC 
closework:open:=FALSE END PROC closework;BOOL PROC workopened:IF NOT 
initialized(packet)THEN closeworkFI ;openEND PROC workopened;BOOL PROC 
workclosed:NOT workopenedEND PROC workclosed;PROC initcheckrerun:oldsession:=
sessionEND PROC initcheckrerun;PROC checkrerun:IF session<>oldsessionTHEN 
closework;errorstop("Diskettenzugriff im RERUN")FI .END PROC checkrerun;PROC 
hdversion(BOOL CONST status):hdflag:=statusEND PROC hdversion;BOOL PROC 
hdversion:hdflagEND PROC hdversion;END PACKET open;