diff --git a/cmd/http/main.go b/cmd/http/main.go
index c1b1d54..34e2ed0 100644
--- a/cmd/http/main.go
+++ b/cmd/http/main.go
@@ -71,16 +71,17 @@ func Main() {
 				return
 			}
 
+			reqF := f
+			if queryF := r.URL.Query().Get("f"); queryF != "" {
+				queryF = path.Join("http", queryF)
+				reqF, err = ledger.NewFiles(queryF)
+				if err != nil {
+					panic(err)
+				}
+			}
+
 			switch r.URL.Path {
 			case "/api/transactions":
-				reqF := f
-				if queryF := r.URL.Query().Get("f"); queryF != "" {
-					queryF = path.Join("http", queryF)
-					reqF, err = ledger.NewFiles(queryF)
-					if err != nil {
-						panic(err)
-					}
-				}
 				lastNLines, err := reqF.TempGetLastNLines(20)
 				if err != nil {
 					panic(err)
@@ -104,7 +105,10 @@ func Main() {
 				if err := json.NewDecoder(r.Body).Decode(&lines); err != nil {
 					panic(err)
 				}
-				http.Error(w, "not done yet", http.StatusNotImplemented)
+				if err := reqF.TempSetLastNLines(20, lines); err != nil {
+					http.Error(w, err.Error(), http.StatusBadRequest)
+				}
+				w.WriteHeader(http.StatusResetContent)
 				return
 			}
 
diff --git a/cmd/http/public/transactions.html b/cmd/http/public/transactions.html
index cccf5b3..342e322 100644
--- a/cmd/http/public/transactions.html
+++ b/cmd/http/public/transactions.html
@@ -79,6 +79,7 @@
       }
       function loadLastNLines(lastNLines) {
         var result = `<form onsubmit="setLastNLines(this); return false;" action="#">`
+        result += `  <div>${f}</div>`
         result += `  <textarea name="lastNLines">`
         for (var k in lastNLines) {
           result += lastNLines[k] + "\n"