diff --git a/main.go b/main.go
index 3f957e4..fe8ad62 100755
--- a/main.go
+++ b/main.go
@@ -99,6 +99,7 @@ func endpoints(foo http.HandlerFunc) http.HandlerFunc {
 				fmt.Fprintln(w, err.Error())
 			}
 		} else {
+			setContentTypeIfMedia(w, r)
 			foo(w, r)
 		}
 	}
@@ -201,3 +202,18 @@ func toRealPath(p string) string {
 	d := path.Join(fs.Get("d").GetString())
 	return path.Join(d, p)
 }
+
+func setContentTypeIfMedia(w http.ResponseWriter, r *http.Request) {
+	switch path.Ext(r.URL.Path) {
+	case ".mp4":
+		w.Header().Set("Content-Type", "video/mp4")
+	case ".webm":
+		w.Header().Set("Content-Type", "video/webm")
+	case ".mkv":
+		w.Header().Set("Content-Type", "video/x-matroska")
+	case ".mp3":
+		w.Header().Set("Content-Type", "audio/mpeg3")
+	case ".epub", ".mobi":
+		w.Header().Set("Content-Disposition", "attachment")
+	}
+}
diff --git a/public/DIR2/e.md b/public/DIR2/e.md
old mode 100644
new mode 100755
diff --git a/public/b.md b/public/b.md
old mode 100644
new mode 100755