diff --git a/trunk/research/librtmp/srs_detect_rtmp.c b/trunk/research/librtmp/srs_detect_rtmp.c
index f98d4cbbc..4e5f400eb 100644
--- a/trunk/research/librtmp/srs_detect_rtmp.c
+++ b/trunk/research/librtmp/srs_detect_rtmp.c
@@ -31,6 +31,7 @@ gcc srs_detect_rtmp.c ../../objs/lib/srs_librtmp.a -g -O0 -lstdc++ -o srs_detect
 
 int main(int argc, char** argv)
 {
+    int ret = 0;
     srs_rtmp_t rtmp;
     
     // time
@@ -62,7 +63,7 @@ int main(int argc, char** argv)
             "For example:\n"
             "   %s rtmp://127.0.0.1:1935/live/livestream 3 10\n",
             argv[0]);
-        int ret = 1;
+        ret = 1;
         exit(ret);
         return ret;
     }
@@ -79,39 +80,40 @@ int main(int argc, char** argv)
     
     if (duration <= 0 || timeout <= 0) {
         printf("duration and timeout must be positive.\n");
-        exit(1);
-        return 1;
+        ret = 1;
+        exit(ret);
+        return ret;
     }
     
     rtmp = srs_rtmp_create(rtmp_url);
     
-    if (__srs_dns_resolve(rtmp) != 0) {
+    if ((ret = __srs_dns_resolve(rtmp)) != 0) {
         printf("dns resolve failed.\n");
         goto rtmp_destroy;
     }
     printf("dns resolve success\n");
     time_dns_resolve = srs_get_time_ms();
     
-    if (__srs_connect_server(rtmp) != 0) {
+    if ((ret = __srs_connect_server(rtmp)) != 0) {
         printf("socket connect failed.\n");
         goto rtmp_destroy;
     }
     printf("socket connect success\n");
     time_socket_connect = srs_get_time_ms();
     
-    if (__srs_do_simple_handshake(rtmp) != 0) {
+    if ((ret = __srs_do_simple_handshake(rtmp)) != 0) {
         printf("do simple handshake failed.\n");
         goto rtmp_destroy;
     }
     printf("do simple handshake success\n");
     
-    if (srs_connect_app(rtmp) != 0) {
+    if ((ret = srs_connect_app(rtmp)) != 0) {
         printf("connect vhost/app failed.\n");
         goto rtmp_destroy;
     }
     printf("connect vhost/app success\n");
     
-    if (srs_play_stream(rtmp) != 0) {
+    if ((ret = srs_play_stream(rtmp)) != 0) {
         printf("play stream failed.\n");
         goto rtmp_destroy;
     }
@@ -119,7 +121,7 @@ int main(int argc, char** argv)
     time_play_stream = srs_get_time_ms();
     
     for (;;) {
-        if (srs_read_packet(rtmp, &type, &timestamp, &data, &size) != 0) {
+        if ((ret = srs_read_packet(rtmp, &type, &timestamp, &data, &size)) != 0) {
             goto rtmp_destroy;
         }
         printf("got packet: type=%s, time=%d, size=%d\n", srs_type2string(type), timestamp, size);
@@ -147,6 +149,7 @@ rtmp_destroy:
     
     // print result to stderr.
     fprintf(stderr, "{"
+        "\"%s\":%d, " //#0
         "\"%s\":%d, " //#1
         "\"%s\":%d, " // #2
         "\"%s\":%d, " // #3
@@ -155,7 +158,8 @@ rtmp_destroy:
         "\"%s\":%d, " // #6
         "\"%s\":%d, " // #7
         "\"%s\":%d, " // #8
-        "%s%s%s}",
+        "%s%s%s%s}",
+        "code", ret, //#0
         // total = dns + tcp_connect + start_play + first_packet + last_packet
         "total", (int)(time_cleanup - time_startup), //#1
         "dns", (int)(time_dns_resolve - time_startup), //#2
@@ -171,7 +175,8 @@ rtmp_destroy:
         // unit in ms.
         "\"unit\": \"ms\",",
         "\"remark0\": \"total = dns + tcp_connect + start_play + first_packet + last_packet\",",
-        "\"remark1\": \"delay = stream - (time_cleanup - time_first_packet)\""
+        "\"remark1\": \"delay = stream - (time_cleanup - time_first_packet)\"",
+        "\"remark2\": \"if code is not 0, user must ignore all data\""
     );
     printf("\n");
     
diff --git a/trunk/src/kernel/srs_kernel_error.hpp b/trunk/src/kernel/srs_kernel_error.hpp
index 7636038c5..cd57899d2 100644
--- a/trunk/src/kernel/srs_kernel_error.hpp
+++ b/trunk/src/kernel/srs_kernel_error.hpp
@@ -51,6 +51,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define ERROR_SOCKET_WRITE                  209
 #define ERROR_SOCKET_WAIT                   210
 #define ERROR_SOCKET_TIMEOUT                211
+#define ERROR_SOCKET_CONNECT                212
 //#define ERROR_SOCKET_GET_LOCAL_IP           212
 
 #define ERROR_RTMP_PLAIN_REQUIRED           300
diff --git a/trunk/src/libs/srs_lib_simple_socket.cpp b/trunk/src/libs/srs_lib_simple_socket.cpp
index d212a6f01..191208fde 100644
--- a/trunk/src/libs/srs_lib_simple_socket.cpp
+++ b/trunk/src/libs/srs_lib_simple_socket.cpp
@@ -57,7 +57,7 @@ SimpleSocketStream::~SimpleSocketStream()
 int SimpleSocketStream::create_socket()
 {
     if((fd = ::socket(AF_INET, SOCK_STREAM, 0)) < 0){
-        return -1;
+        return ERROR_SOCKET_CREATE;
     }
 
     return ERROR_SUCCESS;
@@ -71,7 +71,7 @@ int SimpleSocketStream::connect(const char* server_ip, int port)
     addr.sin_addr.s_addr = inet_addr(server_ip);
     
     if(::connect(fd, (const struct sockaddr*)&addr, sizeof(sockaddr_in)) < 0){
-        return -1;
+        return ERROR_SOCKET_CONNECT;
     }
 
     return ERROR_SUCCESS;