diff --git a/TelegramBaseTest/Program.cs b/TelegramBaseTest/Program.cs
index d2b7b63..f79b7f2 100644
--- a/TelegramBaseTest/Program.cs
+++ b/TelegramBaseTest/Program.cs
@@ -21,13 +21,19 @@ namespace TelegramBaseTest
             bb.SystemCalls.Add("/start");
             bb.SystemCalls.Add("/form1");
             bb.SystemCalls.Add("/form2");
-
             bb.SystemCalls.Add("/params");
 
             bb.SystemCall += async (s, en) =>
             {
                 switch (en.Command)
                 {
+                    case "/start":
+
+                        var start = new Start();
+
+                        await en.Device.ActiveForm.NavigateTo(start);
+
+                        break;
                     case "/form1":
 
                         var form1 = new TestForm();
@@ -47,8 +53,10 @@ namespace TelegramBaseTest
                     case "/params":
 
                         String m = en.Parameters.DefaultIfEmpty("").Aggregate((a, b) => a + " and " + b);
+                        
+                        await en.Device.Send("Your parameters are: " + m, replyTo: en.Device.LastMessageId);
 
-                        await en.Device.Send("Your parameters are " + m, replyTo: en.Device.LastMessage);
+                        en.Handled = true;
 
                         break;
                 }
diff --git a/TelegramBotBase/Base/FormBase.cs b/TelegramBotBase/Base/FormBase.cs
index d5c7d23..e69f443 100644
--- a/TelegramBotBase/Base/FormBase.cs
+++ b/TelegramBotBase/Base/FormBase.cs
@@ -44,6 +44,10 @@ namespace TelegramBotBase.Form
             
         }
 
+        /// <summary>
+        /// Gets invoked if gets navigated to this form
+        /// </summary>
+        /// <returns></returns>
         public virtual async Task Opened()
         {
 
@@ -62,17 +66,31 @@ namespace TelegramBotBase.Form
 
         }
 
+        /// <summary>
+        /// Gets invoked if the form gets loaded and on every message belongs to this context
+        /// </summary>
+        /// <param name="message"></param>
+        /// <returns></returns>
         public virtual async Task Load(MessageResult message)
         {
 
         }
 
+        /// <summary>
+        /// Gets invoked if the user has clicked a button.
+        /// </summary>
+        /// <param name="message"></param>
+        /// <returns></returns>
         public virtual async Task Action(MessageResult message)
         {
 
         }
 
-
+        /// <summary>
+        /// Gets invoked at the end of the cycle to "Render" text, images, buttons, etc...
+        /// </summary>
+        /// <param name="message"></param>
+        /// <returns></returns>
         public virtual async Task Render(MessageResult message)
         {
 
diff --git a/TelegramBotBase/BotBase.cs b/TelegramBotBase/BotBase.cs
index 61030ea..2613b60 100644
--- a/TelegramBotBase/BotBase.cs
+++ b/TelegramBotBase/BotBase.cs
@@ -42,6 +42,8 @@ namespace TelegramBotBase
 
         private static object __evSystemCall = new object();
 
+        public delegate Task SystemCallEventHandler(object sender, SystemCallEventArgs e);
+
         private static object __evException = new object();
 
         private static object __evUnhandledCall = new object();
@@ -220,7 +222,10 @@ namespace TelegramBotBase
             if (e.IsSystemCall && this.SystemCalls.Contains(e.SystemCommand))
             {
                 var sce = new SystemCallEventArgs(e.SystemCommand, e.SystemCallParameters, e.Message, ds.DeviceId, ds);
-                OnSystemCall(sce);
+                await OnSystemCall(sce);
+
+                if (sce.Handled)
+                    return;
             }
 
             FormBase activeForm = null;
@@ -377,21 +382,13 @@ namespace TelegramBotBase
         /// <summary>
         /// Will be called if a system call gets raised
         /// </summary>
-        public event EventHandler<SystemCallEventArgs> SystemCall
-        {
-            add
-            {
-                this.__Events.AddHandler(__evSystemCall, value);
-            }
-            remove
-            {
-                this.__Events.RemoveHandler(__evSystemCall, value);
-            }
-        }
+        public event SystemCallEventHandler SystemCall;
 
-        public void OnSystemCall(SystemCallEventArgs e)
+
+        public async Task OnSystemCall(SystemCallEventArgs e)
         {
-            (this.__Events[__evSystemCall] as EventHandler<SystemCallEventArgs>)?.Invoke(this, e);
+            if (this.SystemCall != null)
+                await SystemCall(this, e);
         }
 
         /// <summary>
diff --git a/TelegramBotBase/Properties/AssemblyInfo.cs b/TelegramBotBase/Properties/AssemblyInfo.cs
index 454c5df..7a5e26e 100644
--- a/TelegramBotBase/Properties/AssemblyInfo.cs
+++ b/TelegramBotBase/Properties/AssemblyInfo.cs
@@ -32,5 +32,5 @@ using System.Runtime.InteropServices;
 // Sie können alle Werte angeben oder die standardmäßigen Build- und Revisionsnummern 
 // übernehmen, indem Sie "*" eingeben:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("1.3.1.0")]
-[assembly: AssemblyFileVersion("1.3.1.0")]
+[assembly: AssemblyVersion("1.3.1.2")]
+[assembly: AssemblyFileVersion("1.3.1.2")]