diff --git a/Server/Client.cs b/Server/Client.cs
index 3843f52..2184dcf 100644
--- a/Server/Client.cs
+++ b/Server/Client.cs
@@ -100,9 +100,14 @@ namespace Server
                         handleLogin(payloadbytes);
                         break;
                     case DataParser.LOGIN_DOCTOR:
-                        handleLogin(payloadbytes);
-                        communication.doctor = this;
-                        Console.WriteLine("Set doctor to " + communication.doctor + " , this is " + this);
+                        if (communication.doctor != null)
+                            return;
+
+                        if (handleLogin(payloadbytes))
+                        {
+                            communication.doctor = this;
+                            Console.WriteLine("Set doctor to " + communication.doctor + " , this is " + this);
+                        }
                         break;
                     case DataParser.START_SESSION:
                         this.saveData = new SaveData(Directory.GetCurrentDirectory() + "/" + this.username + "/" + sessionStart.ToString("yyyy-MM-dd HH-mm-ss"));
@@ -150,7 +155,7 @@ namespace Server
 
         }
 
-        private void handleLogin(byte[] payloadbytes)
+        private bool handleLogin(byte[] payloadbytes)
         {
             string username;
             string password;
@@ -164,6 +169,7 @@ namespace Server
                     sendMessage(DataParser.getLoginResponse("OK"));
                     sendMessage(DataParser.getStartSessionJson());
                     communication.NewLogin(this);
+                    return true;
                 }
                 else
                 {
@@ -174,6 +180,7 @@ namespace Server
             {
                 sendMessage(DataParser.getLoginResponse("invalid json"));
             }
+            return false;
         }
 
         public void sendMessage(byte[] message)