diff --git a/.gitignore b/.gitignore
index 79dd72f..c0b8dec 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,5 @@
 mkinvoice
-makefont
+makefont/makefont
 temp/*
 qr-images/*
 output/*
diff --git a/makefont.go b/makefont/makefont.go
similarity index 100%
rename from makefont.go
rename to makefont/makefont.go
diff --git a/mkinvoice.go b/mkinvoice.go
index e5274a1..dca9102 100644
--- a/mkinvoice.go
+++ b/mkinvoice.go
@@ -2,68 +2,73 @@ package main
 
 import (
 	"fmt"
-	"github.com/jung-kurt/gofpdf"
-	"gopkg.in/yaml.v2"
 	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
 	"path/filepath"
+
+	"github.com/jung-kurt/gofpdf"
+	"gopkg.in/yaml.v2"
 )
 
+// Metadata type
 type Metadata struct {
-	Invoice_nr   string
-	Invoice_info string
-	Invoice_date string
+	InvoiceNr    string
+	InvoiceInfo  string
+	InvoiceDdate string
 	Vat          float64
 	Account      string
-	Due_date     string
+	DueDate      string
 }
 
+// Address type
 type Address struct {
 	Name   string
 	Street string
 	Zip    string
 	City   string
-	Tel_no string
+	TelNo  string
 	Email  string
 }
 
+// InvoiceItem type
 type InvoiceItem struct {
-	Text          string
-	Quantity      float64
-	Pice_per_unit float64
+	Text        string
+	Quantity    float64
+	PicePerUnit float64
 }
 
+// InvoiceData type
 type InvoiceData struct {
-	Metadata        Metadata
-	Sender_address  Address
-	Billing_address Address
-	Item            []InvoiceItem
+	Metadata       Metadata
+	SenderAddress  Address
+	BillingAddress Address
+	Item           []InvoiceItem
 }
 
 /* global variable declaration */
 var pdf *gofpdf.Fpdf
-var y_pos float64
-var invoice_data InvoiceData
-var prog_dir string
+var yPos float64
+var invoiceData InvoiceData
+var progDir string
 
-const margin_top = 7
-const logo_top = 6
-const logo_height = 20
-const line_spacing = 5
-const address_top = 50
-const line1_top = 100
-const tabstop_left = 20
-const tabstop_left_2 = 32
-const tabstop_address = 120
-const tabstop_count = 10
-const tabstop_price = 10
-const tabstop_total = 170
-const tabstop_logo = 155
-const tabstop_right = 200
+const marginTop = 7
+const logoTop = 6
+const logoHeight = 20
+const lineSpacing = 5
+const addressTop = 50
+const line1Top = 100
+const tabstopLeft = 20
+const tabstopLeftAlt = 32
+const tabstopAddress = 120
+const tabstopCount = 10
+const tabstopPrice = 10
+const tabstopTotal = 170
+const tabstopLogo = 155
+const tabstopRight = 200
 
-func ReadInvoiceData(filename string) {
+func readInvoiceData(filename string) {
 	data, err := ioutil.ReadFile(filename)
 	if err != nil {
 		log.Fatal(err)
@@ -71,16 +76,16 @@ func ReadInvoiceData(filename string) {
 
 	//fmt.Printf("File contents: %s", data)
 
-	err = yaml.Unmarshal([]byte(data), &invoice_data)
+	err = yaml.Unmarshal([]byte(data), &invoiceData)
 	if err != nil {
 		log.Fatalf("error: %v", err)
 	}
 
-	fmt.Printf("--- t:\n%v\n\n", invoice_data)
-	fmt.Printf("%s\n", invoice_data.Billing_address.Name)
+	fmt.Printf("--- t:\n%v\n\n", invoiceData)
+	fmt.Printf("%s\n", invoiceData.BillingAddress.Name)
 }
 
-func WriteText(x float64, y float64, text string, alignStr ...string) {
+func writeText(x float64, y float64, text string, alignStr ...string) {
 	tr := pdf.UnicodeTranslatorFromDescriptor("")
 	align := "LT"
 	if len(alignStr) > 0 {
@@ -90,7 +95,7 @@ func WriteText(x float64, y float64, text string, alignStr ...string) {
 	pdf.CellFormat(0, 11, tr(text), "", 0, align, false, 0, "")
 }
 
-func SetupInvoice() {
+func setupInvoice() {
 	pdf = gofpdf.New("P", "mm", "A4", "")
 	pdf.SetMargins(0, 0, 0)
 	pdf.SetFontLocation("fonts")
@@ -99,64 +104,64 @@ func SetupInvoice() {
 	pdf.SetFont("Dejavusans", "", 10)
 }
 
-func PrintPageHeader(firstPage bool) {
+func printPageHeader(firstPage bool) {
 	var opt gofpdf.ImageOptions
 
 	pdf.AddPage()
-	y_pos = margin_top
+	yPos = marginTop
 	pdf.SetFont("Dejavusans-Bold", "", 10)
-	WriteText(tabstop_left, y_pos, "nbit Informatik GmbH")
+	writeText(tabstopLeft, yPos, "nbit Informatik GmbH")
 	pdf.SetFont("Dejavusans", "", 10)
-	y_pos = y_pos + line_spacing
-	WriteText(tabstop_left, y_pos, "Kirchweg 2")
-	y_pos = y_pos + line_spacing
-	WriteText(tabstop_left, y_pos, "3510 Konolfingen")
-	y_pos = y_pos + line_spacing
-	y_pos = y_pos + line_spacing
-	WriteText(tabstop_left, y_pos, "Tel.")
-	WriteText(tabstop_left_2, y_pos, "+41 31 792 00 40")
-	y_pos = y_pos + line_spacing
-	WriteText(tabstop_left, y_pos, "EMail")
-	WriteText(tabstop_left_2, y_pos, "joerg.lehmann@nbit.ch")
-	y_pos = y_pos + line_spacing
+	yPos = yPos + lineSpacing
+	writeText(tabstopLeft, yPos, "Kirchweg 2")
+	yPos = yPos + lineSpacing
+	writeText(tabstopLeft, yPos, "3510 Konolfingen")
+	yPos = yPos + lineSpacing
+	yPos = yPos + lineSpacing
+	writeText(tabstopLeft, yPos, "Tel.")
+	writeText(tabstopLeftAlt, yPos, "+41 31 792 00 40")
+	yPos = yPos + lineSpacing
+	writeText(tabstopLeft, yPos, "EMail")
+	writeText(tabstopLeftAlt, yPos, "joerg.lehmann@nbit.ch")
+	yPos = yPos + lineSpacing
 
 	opt.ImageType = "png"
 	opt.ReadDpi = true
-	pdf.ImageOptions("logos/nbit-logo.png", tabstop_logo, logo_top, 0, logo_height, false, opt, 0, "")
+	pdf.ImageOptions("logos/nbit-logo.png", tabstopLogo, logoTop, 0, logoHeight, false, opt, 0, "")
 }
 
-func PrintAddress() {
-	fmt.Printf("Blabla: %s\n", invoice_data.Billing_address.Name)
-	y_pos = address_top
-	WriteText(tabstop_address, y_pos, invoice_data.Billing_address.Name)
-	y_pos = y_pos + line_spacing
-	WriteText(tabstop_address, y_pos, invoice_data.Billing_address.Street)
-	y_pos = y_pos + line_spacing
-	WriteText(tabstop_address, y_pos, invoice_data.Billing_address.Zip+" "+invoice_data.Billing_address.City)
-	y_pos = y_pos + line_spacing
+func printAddress() {
+	fmt.Printf("Blabla: %s\n", invoiceData.BillingAddress.Name)
+	yPos = addressTop
+	writeText(tabstopAddress, yPos, invoiceData.BillingAddress.Name)
+	yPos = yPos + lineSpacing
+	writeText(tabstopAddress, yPos, invoiceData.BillingAddress.Street)
+	yPos = yPos + lineSpacing
+	writeText(tabstopAddress, yPos, invoiceData.BillingAddress.Zip+" "+invoiceData.BillingAddress.City)
+	yPos = yPos + lineSpacing
 
-	pdf.Line(tabstop_left, line1_top, tabstop_right, line1_top)
+	pdf.Line(tabstopLeft, line1Top, tabstopRight, line1Top)
 }
 
-func PrintQR() {
+func printQR() {
 	var opt gofpdf.ImageOptions
 
-	cmd := exec.Command(filepath.Join(prog_dir, "qrbill.sh"),
-		"--account", invoice_data.Metadata.Account,
+	cmd := exec.Command(filepath.Join(progDir, "qrbill.sh"),
+		"--account", invoiceData.Metadata.Account,
 		"--amount", "123.00",
-		"--creditor-name", invoice_data.Sender_address.Name,
-		"--creditor-street", invoice_data.Sender_address.Street,
-		"--creditor-postalcode", invoice_data.Sender_address.Zip,
-		"--creditor-city", invoice_data.Sender_address.City,
-		"--extra-infos", invoice_data.Metadata.Invoice_info,
-		"--debtor-name", invoice_data.Billing_address.Name,
-		"--debtor-street", invoice_data.Billing_address.Street,
-		"--debtor-postalcode", invoice_data.Billing_address.Zip,
-		"--debtor-city", invoice_data.Billing_address.City,
-		"--due-date", invoice_data.Metadata.Due_date,
+		"--creditor-name", invoiceData.SenderAddress.Name,
+		"--creditor-street", invoiceData.SenderAddress.Street,
+		"--creditor-postalcode", invoiceData.SenderAddress.Zip,
+		"--creditor-city", invoiceData.SenderAddress.City,
+		"--extra-infos", invoiceData.Metadata.InvoiceInfo,
+		"--debtor-name", invoiceData.BillingAddress.Name,
+		"--debtor-street", invoiceData.BillingAddress.Street,
+		"--debtor-postalcode", invoiceData.BillingAddress.Zip,
+		"--debtor-city", invoiceData.BillingAddress.City,
+		"--due-date", invoiceData.Metadata.DueDate,
 		"--language", "de")
 	cmd.Env = append(os.Environ(),
-		"INVNO="+invoice_data.Metadata.Invoice_nr,
+		"INVNO="+invoiceData.Metadata.InvoiceNr,
 	)
 	stdoutStderr, err := cmd.CombinedOutput()
 	fmt.Printf("%s\n", stdoutStderr)
@@ -167,7 +172,7 @@ func PrintQR() {
 
 	opt.ImageType = "jpeg"
 	opt.ReadDpi = true
-	pdf.ImageOptions("qr-images/"+invoice_data.Metadata.Invoice_nr+".jpg", 0, 200, 0, 0, false, opt, 0, "")
+	pdf.ImageOptions("qr-images/"+invoiceData.Metadata.InvoiceNr+".jpg", 0, 200, 0, 0, false, opt, 0, "")
 }
 
 func main() {
@@ -175,20 +180,20 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
-	prog_dir = dir
+	progDir = dir
 
 	if len(os.Args) != 2 {
 		fmt.Printf("usage: mkinvoice <yaml-file>\n")
 		os.Exit(1)
 	}
 
-	ReadInvoiceData(os.Args[1])
-	SetupInvoice()
-	PrintPageHeader(true)
-	PrintAddress()
-	PrintQR()
+	readInvoiceData(os.Args[1])
+	setupInvoice()
+	printPageHeader(true)
+	printAddress()
+	printQR()
 
-	err = pdf.OutputFileAndClose(filepath.Join(prog_dir, "output", invoice_data.Metadata.Invoice_nr+".pdf"))
+	err = pdf.OutputFileAndClose(filepath.Join(progDir, "output", invoiceData.Metadata.InvoiceNr+".pdf"))
 	if err == nil {
 		fmt.Printf("Successfully created invoice\n")
 	} else {