Plugin error with check_hd plugin


Im trying to get the check_hd plugin to work that I got from nagiosexchange but Im running into a problem with the Status Information on the Nagios page. The status that it reports is, **ePN failed to complie /usr/lib/nagios/plugins/check_hd: "Global symbol “$PROGNAME” requires explicit package name at (eval 2) line 21,

Now line 21 in the check_hd plugin is as follows: $PROGNAME = “check_hd”; …I dont know what Im supposed to change if anything and the documentation on the nagiosexchange site didnt help. Has anyone else come across this error or know what I can do to fix this?