diff --git a/example/main.go b/example/main.go
index 1860740..715dbba 100644
--- a/example/main.go
+++ b/example/main.go
@@ -9,8 +9,15 @@ import (
 	"github.com/chzyer/readline"
 )
 
+func usage(w io.Writer) {
+	io.WriteString(w, `
+sayhello: start to display oneline log per second
+bye: quit
+`[1:])
+}
+
 func main() {
-	l, err := readline.New("> ")
+	l, err := readline.New("home -> ")
 	if err != nil {
 		panic(err)
 	}
@@ -24,7 +31,7 @@ func main() {
 		}
 		switch line {
 		case "help":
-			io.WriteString(l.Stderr(), "sayhello: start to display oneline log per second\nbye: quit\n")
+			usage(l.Stderr())
 		case "sayhello":
 			go func() {
 				for _ = range time.Tick(time.Second) {
@@ -33,6 +40,7 @@ func main() {
 			}()
 		case "bye":
 			goto exit
+		case "":
 		default:
 			log.Println("you said:", strconv.Quote(line))
 		}
diff --git a/history.go b/history.go
index 9dac917..e5b488a 100644
--- a/history.go
+++ b/history.go
@@ -47,10 +47,21 @@ func (o *Operation) NextHistory() ([]rune, bool) {
 func (o *Operation) NewHistory(current []rune) {
 	// if just use last command without modify
 	// just clean lastest history
-	if o.current == o.history.Back().Prev() {
-		use := o.current.Value.(*HisItem)
-		if equalRunes(use.Tmp, use.Source) {
-			o.current = o.history.Back()
+	if back := o.history.Back(); back != nil {
+		prev := back.Prev()
+		if prev != nil {
+			use := o.current.Value.(*HisItem)
+			if equalRunes(use.Tmp, prev.Value.(*HisItem).Source) {
+				o.current = o.history.Back()
+				o.current.Value.(*HisItem).Clean()
+				o.historyVer++
+				return
+			}
+		}
+	}
+	if len(current) == 0 {
+		o.current = o.history.Back()
+		if o.current != nil {
 			o.current.Value.(*HisItem).Clean()
 			o.historyVer++
 			return
diff --git a/operation.go b/operation.go
index e0ca9b4..d9dc4c6 100644
--- a/operation.go
+++ b/operation.go
@@ -81,7 +81,6 @@ func (l *Operation) ioloop() {
 			data = data[:len(data)-1] // trim \n
 			l.outchan <- data
 			l.NewHistory(data)
-			debugList(l.history)
 		case CharBackward:
 			l.buf.MoveBackward()
 		case CharForward:
diff --git a/runebuf.go b/runebuf.go
index 6bbb96d..9d75a59 100644
--- a/runebuf.go
+++ b/runebuf.go
@@ -10,15 +10,14 @@ type RuneBuffer struct {
 	idx         int
 	prompt      []byte
 	w           io.Writer
+	hasPrompt   bool
 	lastWritten int
-	printPrompt bool
 }
 
 func NewRuneBuffer(w io.Writer, prompt string) *RuneBuffer {
 	rb := &RuneBuffer{
-		prompt:      []byte(prompt),
-		w:           w,
-		printPrompt: true,
+		prompt: []byte(prompt),
+		w:      w,
 	}
 	return rb
 }
@@ -161,18 +160,24 @@ func (r *RuneBuffer) MoveToLineEnd() {
 }
 
 func (r *RuneBuffer) Refresh(chlen, chidx int) {
-	s := r.Output(len(r.buf)-chlen, r.idx-chidx)
+	s := r.Output(len(r.buf)-chlen, r.idx-chidx, true)
 	r.w.Write(s)
 }
 
 func (r *RuneBuffer) RefreshSet(originLength, originIdx int) {
-	r.w.Write(r.Output(originLength, originIdx))
+	r.w.Write(r.Output(originLength, originIdx, true))
 }
 
-func (r *RuneBuffer) Output(originLength, originIdx int) []byte {
+func (r *RuneBuffer) Output(originLength, originIdx int, prompt bool) []byte {
 	buf := bytes.NewBuffer(nil)
-	buf.Write(bytes.Repeat([]byte{'\b'}, originIdx+len(r.prompt)))
-	buf.Write(r.prompt)
+	buf.Write(bytes.Repeat([]byte{'\b'}, originIdx))
+	if prompt {
+		if r.hasPrompt {
+			buf.Write(bytes.Repeat([]byte{'\b'}, len(r.prompt)))
+		}
+		buf.Write(r.prompt)
+	}
+	r.hasPrompt = prompt
 	buf.Write([]byte(string(r.buf)))
 	if originLength > len(r.buf) {
 		buf.Write(bytes.Repeat([]byte{' '}, originLength-len(r.buf)))
@@ -184,21 +189,29 @@ func (r *RuneBuffer) Output(originLength, originIdx int) []byte {
 
 func (r *RuneBuffer) Clean() {
 	moveToFirst := r.idx
-	moveToFirst += len(r.prompt)
+	if r.hasPrompt {
+		moveToFirst += len(r.prompt)
+	}
 	r.w.Write(bytes.Repeat([]byte{'\b'}, moveToFirst))
-	length := len(r.buf) + len(r.prompt)
-
+	length := len(r.buf)
+	if r.hasPrompt {
+		length += len(r.prompt)
+	}
 	r.w.Write(bytes.Repeat([]byte{' '}, length))
+
 	r.w.Write(bytes.Repeat([]byte{'\b'}, length))
-	r.printPrompt = true
+	r.hasPrompt = false
+}
+
+func (r *RuneBuffer) ResetScreen() {
+	r.w.Write(r.Output(0, 0, false))
 }
 
 func (r *RuneBuffer) Reset() []rune {
 	ret := r.buf
 	r.buf = r.buf[:0]
 	r.idx = 0
-	r.printPrompt = true
-	r.Refresh(-len(ret), r.SetIdx(0))
+	r.hasPrompt = false
 	return ret
 }
 
diff --git a/terminal.go b/terminal.go
index e961d47..c895081 100644
--- a/terminal.go
+++ b/terminal.go
@@ -72,7 +72,6 @@ func (t *Terminal) ioloop() {
 	isEscapeEx := false
 	for {
 		r, _, err := buf.ReadRune()
-		Debug(r, isEscape, isEscapeEx)
 		if err != nil {
 			break
 		}
@@ -87,7 +86,6 @@ func (t *Terminal) ioloop() {
 		} else if isEscapeEx {
 			isEscapeEx = false
 			r = escapeExKey(r)
-			Debug("r:", r)
 		}
 
 		if IsPrintable(r) || r < 0 {
diff --git a/utils.go b/utils.go
index 4cf9592..e159682 100644
--- a/utils.go
+++ b/utils.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"syscall"
+	"time"
 	"unsafe"
 
 	"golang.org/x/crypto/ssh/terminal"
@@ -103,3 +104,8 @@ func equalRunes(a, b []rune) bool {
 	}
 	return true
 }
+
+func sleep(n int) {
+	Debug(n)
+	time.Sleep(2000 * time.Millisecond)
+}