diff --git a/database.go b/database.go
index c840abc..a98b46b 100644
--- a/database.go
+++ b/database.go
@@ -3,6 +3,7 @@ package main
 import (
 	"labix.org/v2/mgo"
 	"labix.org/v2/mgo/bson"
+	"sort"
 )
 
 type Book struct {
@@ -59,3 +60,39 @@ func GetBook(coll *mgo.Collection, query bson.M, r ...int) (books []Book, num in
 	return
 
 }
+
+type tagsList []struct {
+	Subject string "_id"
+	Count   int    "value"
+}
+
+func (t tagsList) Len() int {
+	return len(t)
+}
+func (t tagsList) Less(i, j int) bool {
+	return t[i].Count > t[j].Count
+}
+func (t tagsList) Swap(i, j int) {
+	aux := t[i]
+	t[i] = t[j]
+	t[j] = aux
+}
+
+func GetTags(coll *mgo.Collection) (tagsList, error) {
+	// TODO: cache the tags
+	var mr mgo.MapReduce
+	mr.Map = "function() { " +
+		"this.subject.forEach(function(s) { emit(s, 1); });" +
+		"}"
+	mr.Reduce = "function(tag, vals) { " +
+		"var count = 0;" +
+		"vals.forEach(function() { count += 1; });" +
+		"return count;" +
+		"}"
+	var result tagsList
+	_, err := coll.Find(nil).MapReduce(&mr, &result)
+	if err == nil {
+		sort.Sort(result)
+	}
+	return result, err
+}
diff --git a/trantor.go b/trantor.go
index 3fdc081..03fef9e 100644
--- a/trantor.go
+++ b/trantor.go
@@ -5,7 +5,6 @@ import (
 	"labix.org/v2/mgo"
 	"labix.org/v2/mgo/bson"
 	"net/http"
-	"sort"
 )
 
 const (
@@ -15,6 +14,7 @@ const (
 	NEW_BOOKS_COLL = "new"
 	USERS_COLL     = "users"
 	PASS_SALT      = "ImperialLibSalt"
+	TAGS_DISPLAY   = 50
 )
 
 type aboutData struct {
@@ -88,48 +88,20 @@ type indexData struct {
 	Tags  []string
 }
 
-type tagsList []struct {
-	Subject string "_id"
-	Count int "value"
-}
-func (t tagsList) Len() int {
-	return len(t)
-}
-func (t tagsList) Less(i, j int) bool {
-	return t[i].Count > t[j].Count
-}
-func (t tagsList) Swap(i, j int) {
-	aux := t[i]
-	t[i] = t[j]
-	t[j] = aux
-}
-
 func indexHandler(coll *mgo.Collection) func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		var data indexData
 
 		/* get the tags */
-		// TODO: cache the tags
-		var mr mgo.MapReduce
-		mr.Map = "function() { " +
-			"this.subject.forEach(function(s) { emit(s, 1); });" +
-		"}"
-		mr.Reduce = "function(tag, vals) { " +
-			"var count = 0;" +
-			"vals.forEach(function() { count += 1; });" +
-			"return count;" +
-		"}"
-		var result tagsList
-		_, err := coll.Find(nil).MapReduce(&mr, &result)
+		tags, err := GetTags(coll)
 		if err == nil {
-			sort.Sort(result)
-			length := len(result)
-			if length > 50 {
-				length = 50
+			length := len(tags)
+			if length > TAGS_DISPLAY {
+				length = TAGS_DISPLAY
 			}
 			data.Tags = make([]string, length)
-			for i, tag := range result {
-				if i == 50 {
+			for i, tag := range tags {
+				if i == TAGS_DISPLAY {
 					break /* display only 50 */
 				}
 				if tag.Subject != "" {
diff --git a/upload.go b/upload.go
index 3ab5b94..c75a3b4 100644
--- a/upload.go
+++ b/upload.go
@@ -187,7 +187,7 @@ func parseDate(date []string) string {
 	return strings.Replace(date[0], "Unspecified: ", "", -1)
 }
 
-func keywords(b map[string] interface{}) (k []string) {
+func keywords(b map[string]interface{}) (k []string) {
 	title, _ := b["title"].(string)
 	k = strings.Split(title, " ")
 	author, _ := b["author"].([]string)
@@ -202,7 +202,7 @@ func keywords(b map[string] interface{}) (k []string) {
 }
 
 func parseFile(coll *mgo.Collection, path string) (string, error) {
-	book := map[string] interface{}{}
+	book := map[string]interface{}{}
 
 	e, err := epub.Open(path, 0)
 	if err != nil {