diff --git a/script/local.py b/script/local.py
index d766906..bceba50 100644
--- a/script/local.py
+++ b/script/local.py
@@ -16,14 +16,14 @@ class RobotTCP(TcpDevice):
          self.trailer = "\n"
          self.msg_id = 0
 
-    def sendReceive(self, msg):
-        tx = self.header if (self.header != None) else  self.header
+    def sendReceive(self, msg):        
+        tx = self.header if (self.header != None) else  ""
         id = "%03d" % self.msg_id
-        self.msg_id = (self.msg_id+1)%1000
-        tx = tx + id + " " + msg
+        self.msg_id = (self.msg_id+1)%1000        
+        tx = tx + id + " " + msg        
         self.getLogger().finer("TX = " +  str(tx))
-        if (self.trailer != None): cmd = cmd + self.trailer
-        rx = self.sendReceive(cmd, None, self.trailer , 0,  self.timeout, self.retries).strip()
+        if (self.trailer != None): tx = tx + self.trailer
+        rx = self.sendReceive(tx, None, self.trailer , 0,  self.timeout, self.retries).strip()
         self.getLogger().finer("RX = " + str(rx))
         if rx[:3] != id:
             raise Exception("Received invalid message id")