diff --git a/go.mod b/go.mod
index 3716411..f195170 100644
--- a/go.mod
+++ b/go.mod
@@ -1 +1,3 @@
 module q5
+
+go 1.15
diff --git a/listhead.go b/listhead.go
index af5c8a6..04248bd 100644
--- a/listhead.go
+++ b/listhead.go
@@ -34,6 +34,7 @@ func (this *ListHead) Replace(pnew *ListHead) {
 	pnew.next = this.next
 	pnew.next.prev = pnew
 	pnew.prev = this.prev
+	pnew.prev.next = pnew
 	pnew.data = this.data
 }
 
diff --git a/timer.go b/timer.go
index 0f3f4aa..4d6cc5d 100644
--- a/timer.go
+++ b/timer.go
@@ -53,12 +53,12 @@ func (this *Timer) Init(
 	this.getTickCount = getTickCount
 	this.gcTime = gcTime
 	this.cacheTimerNum = cacheTimerNum
-	/*this.AddRepeatTimer(
+	this.AddRepeatTimer(
 		this.gcTime,
 		func (params *XParams) {
 
 		},
-		this.gcTimerFunc)*/
+		this.gcTimerFunc)
 }
 
 func (this *Timer) UnInit() {
@@ -151,6 +151,7 @@ func (this *Timer) AddDeadLineTimerEx(
 	if install_func != nil {
 		install_func(timerList, &timerList.params)
 	}
+	this.ModifyTimer(timerList, milli_seconds)
 	return timerList
 }
 
@@ -174,6 +175,7 @@ func (this *Timer) AddRepeatTimerEx(
 	if install_func != nil {
 		install_func(timerList, &timerList.params)
 	}
+	this.ModifyTimer(timerList, milli_seconds)
 	return timerList
 }
 
@@ -197,6 +199,7 @@ func (this *Timer) AddFixedTimerEx(
 	if install_func != nil {
 		install_func(timerList, &timerList.params)
 	}
+	this.ModifyTimer(timerList, milli_seconds)
 	return timerList
 }
 
@@ -279,16 +282,16 @@ func (this *Timer) internalAddTimer(timer_list *TimerList) {
 		index = (uint32)(expires & TVR_MASK)
 		vec = &this.tv1[index]
 	} else if idx < (1 << (TVR_BITS + TVN_BITS)) {
-		index = (uint32)((expires >> TVR_BITS) & TVR_MASK)
+		index = (uint32)((expires >> TVR_BITS) & TVN_MASK)
 		vec = &this.tv2[index]
 	} else if idx < (1 << (TVR_BITS + 2 * TVN_BITS)) {
-		index = (uint32)((expires >> (TVR_BITS + 1 * TVN_BITS)) & TVR_MASK)
+		index = (uint32)((expires >> (TVR_BITS + 1 * TVN_BITS)) & TVN_MASK)
 		vec = &this.tv3[index]
 	} else if idx < (1 << (TVR_BITS + 3 * TVN_BITS)) {
-		index = (uint32)((expires >> (TVR_BITS + 2 * TVN_BITS)) & TVR_MASK)
+		index = (uint32)((expires >> (TVR_BITS + 2 * TVN_BITS)) & TVN_MASK)
 		vec = &this.tv4[index]
 	} else {
-		index = (uint32)((expires >> (TVR_BITS + 3 * TVN_BITS)) & TVR_MASK)
+		index = (uint32)((expires >> (TVR_BITS + 3 * TVN_BITS)) & TVN_MASK)
 		vec = &this.tv5[index]
 	}
 	vec.AddTail(&timer_list.entry)