diff --git a/internal/codec.go b/internal/codec.go
index bb671ca..9c6be76 100644
--- a/internal/codec.go
+++ b/internal/codec.go
@@ -127,7 +127,10 @@ func GetMsgs(soap string) []string {
 func GetErrMsg(soap string) string {
 	r, _ := regexp.Compile(errExp)
 	msg := r.FindAllString(soap, -1)
-	if len(msg) > 0 && len(msg[0]) > 40 {
+	if len(msg) < 1 {
+		return ""
+	}
+	if len(msg[0]) > 40 {
 		size := len(msg[0])
 		return msg[0][54 : size-15]
 	}
diff --git a/internal/codec_test.go b/internal/codec_test.go
index f5382e7..f643648 100644
--- a/internal/codec_test.go
+++ b/internal/codec_test.go
@@ -94,6 +94,8 @@ const (
 	Msg string = `<?xml version="1.0" encoding="UTF-8"?> <msg xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="unisysaodbsis.xsd">   <meta>     <sndr>AODB</sndr>     <seqn>820830</seqn>     <dttm>20180527124442</dttm>     <type>FLOP</type>     <styp>ESTT</styp>   </meta>   <flop>     <flid>10725849</flid>     <ffid>CA-CA4242-A-27MAY181955-D</ffid>     <estt>27MAY181945</estt>   </flop> </msg>`
 
 	ErrMsg string = `<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><soap:Body><soap:Fault><faultcode>soap:Server</faultcode><faultstring>invalid route envent id </faultstring><detail><BHIAFault xmlns="http://ciims.bhia.itdcl.com"><code xmlns="http://msg.ciims.bhia.itdcl.com">20</code><errorMessage xmlns="http://msg.ciims.bhia.itdcl.com">Can not find the event [FLOP-ESTT-ATC-ALL1]</errorMessage></BHIAFault></detail></soap:Fault></soap:Body></soap:Envelope>`
+
+	SendOk string = `<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><soap:Body><ns1:sendResponse xmlns:ns1="http://ciims.bhia.itdcl.com/ExchangeService" /></soap:Body></soap:Envelope>`
 )
 
 func TestSend(t *testing.T) {
@@ -126,3 +128,9 @@ func TestGetErrMsg(t *testing.T) {
 	errMsg := GetErrMsg(ErrMsg)
 	assert.Equal("Can not find the event [FLOP-ESTT-ATC-ALL1]", errMsg)
 }
+
+func TestSendOk(t *testing.T) {
+	assert := assert.New(t)
+	errMsg := GetErrMsg(SendOk)
+	assert.Equal("", errMsg)
+}