diff --git a/check_cisco_qos/trunk/check_cisco_qos.sh b/check_cisco_qos/trunk/check_cisco_qos.sh
index a25d235..f581e97 100755
--- a/check_cisco_qos/trunk/check_cisco_qos.sh
+++ b/check_cisco_qos/trunk/check_cisco_qos.sh
@@ -2,10 +2,24 @@
 
 # ./check_cisco_qos.pl -H  10.18.0.114 -C KB816af -w 10 -c 20  -i ALL -m Call_Signaling
 
-CLASSES=`./check_cisco_qos.pl $@ -i ALL -m ALL -d | grep qos-class| awk '{ print $6 }'`
+PATH=$PATH:/usr/lib/nagios/plugins/:/usr/lib64/nagios/plugins/:/nagios/usr/lib/nagios/plugins
+which check_cisco_qos.pl > /dev/null
+if [ $? -gt 0 ]; then
+	echo "Unknown check_cisco_qos.pl not found in path"
+	exit 3
+fi
+
+CLASSES=`check_cisco_qos.pl $@ -i ALL -m ALL -d | grep qos-class| awk '{ print $6 }'`
+NUM_CLASSES=`echo $CLASSES |wc -w`
+if [ $NUM_CLASSES -lt 1 ]; then
+	echo "Error running check_cisco_qos.pl"
+	echo "Command was: check_cisco_qos.pl $@ -i ALL -m ALL -d"
+	exit 3
+fi
+
 EXIT_CODE=0
 for i in $CLASSES ; do
-	TMP=`./check_cisco_qos.pl $@ -i ALL -m $i`
+	TMP=`check_cisco_qos.pl $@ -i ALL -m $i`
 	STATUS=$?
 	if [ $STATUS -gt $EXIT_CODE ]; then
 		EXIT_CODE=$STATUS