diff --git a/.gitignore b/.gitignore
index 2235288..289730e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 *.bak
 *.pdf
+last_invoice_number
diff --git a/gen.sh b/gen.sh
index 6d6f0f1..dbb96e5 100755
--- a/gen.sh
+++ b/gen.sh
@@ -1,24 +1,70 @@
 #!/bin/bash
 
+# What you charge an hour
+RATE=50
+
+short_help() {
+	echo "$0 <file.csv> <Paying Company Name> [output file]"
+	echo "--help for help"
+}
+long_help() {
+	short_help
+	echo ""
+	echo "The csv file should be setup as:"
+	echo ""
+	echo "Job <string>, Hours <number>"
+	echo ""
+	echo "With no empty line at the end."
+	echo "Paying company name is any string"
+	echo "The output argument is optional and will by default output to invoice-<num>.pdf"
+}
+
+CSV=""
 if [[ -z $1 ]]; then
-	echo First argument must be a csv containing: jobs,hours
+	short_help
 	exit
+elif [[ $1 = "--help" ]]; then
+	long_help	
+	exit
+else
+	CSV=$1
 fi
 
+COMPANY=""
 if [[ -z $2 ]]; then
-	echo Second argument must be the name of who you are billing
+	short_help
 	exit
+else
+	COMPANY=$2
 fi
 
+# Increment a global invoice number
+INV_FILE="last_invoice_number"
+INV_NUM=0
+if [[ -f $INV_FILE ]]; then
+	INV_NUM=$(expr $(cat $INV_FILE) + 1)
+else
+	INV_NUM=1
+fi
+echo $INV_NUM > $INV_FILE
 
+# 3rd argument is output location (optional)
+OUTPUT="invoice-${INV_NUM}.pdf"
+if [[ ! -z $3 ]]; then
+	OUTPUT=$3
+fi
+
+# Parse the CSV into: Label;Hrs;Cost
 TMP=$(mktemp)
-cat $1 | awk -F, '{ sum += $2 }; { print $1 ";" $2 ";" $2 * 50 }  END { print "Total" ";" sum ";" sum * 50}' > $TMP
+cat $CSV | RATE=$RATE awk -F, '{ sum += $2 }; { print $1 ";" $2 ";" $2 * ENVIRON["RATE"] }  END { print "Total" ";" sum ";" sum * ENVIRON["RATE"]}' > $TMP
 
-# Last line
-# Everything but the last line
+# TOTAL = Last line
+# BODY = Everything but the last line
 TOTAL=$(cat $TMP | tail -n 1) \
 	BODY=$(cat $TMP | head -n -1) \
-	COMPANY=$2 \
-	envsubst < template.mm | groff -t -mm -T pdf > output.pdf
+	COMPANY=$COMPANY \
+	INVOICE_NUM=$INV_NUM \
+	RATE=$RATE \
+	envsubst < template.mm | groff -t -mm -T pdf > $OUTPUT
 
 rm $TMP
diff --git a/template.mm b/template.mm
index 16792bd..fd6e752 100644
--- a/template.mm
+++ b/template.mm
@@ -16,7 +16,7 @@ LR.
 Cooies Unlimited;(123) 456-7890
 123 Sesame St.;cookie@example.com
 Dumpster 1;\*[DT]
-Nicevile FL;Invoice ID #001
+Nicevile FL;Invoice ID #${INVOICE_NUM}
 .TE
 
 \# Billing info
@@ -36,6 +36,6 @@ ${TOTAL}
 .TE
 
 .PP
-If you have any questions please reach out at any of the provided contacts above.
+Hours were charged at $${RATE}/hr. If you have any questions please reach out at any of the provided contacts above.
 Thank you for your business!