diff --git a/StormChatWPF/LogWindow.xaml b/StormChatWPF/LogWindow.xaml
index 12d5f90..86d517f 100644
--- a/StormChatWPF/LogWindow.xaml
+++ b/StormChatWPF/LogWindow.xaml
@@ -5,8 +5,9 @@
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:local="clr-namespace:StormChatWPF"
         mc:Ignorable="d"
-        Title="StormChat" Height="450" Width="800"
-		Icon="UI/闪电.png">
+        Title="WelCome" Height="450" Width="800"
+		Icon="UI/Resources/闪电.png" 
+		WindowStartupLocation="CenterScreen">
 	<Grid Height="418" VerticalAlignment="Stretch" Margin="2,1,1,1">
 		<Grid.ColumnDefinitions>
 			<ColumnDefinition Width="200*"/>
@@ -19,7 +20,7 @@
 			<RowDefinition Height="150*"/>
 			<RowDefinition Height="150*"/>
 		</Grid.RowDefinitions>
-		<Image x:Name="LogBackground"  Grid.ColumnSpan="4" Height="268" Margin="10,10,10,0" Grid.RowSpan="2" VerticalAlignment="Top" Source="UI/登录界面底.png"/>
+		<Image x:Name="LogBackground"  Grid.ColumnSpan="4" Height="268" Margin="10,10,10,0" Grid.RowSpan="2" VerticalAlignment="Top" Source="pack://application:,,,/UI/Resources/登录界面底.png"/>
 		<Button x:Name="Login_button" Content="LogIn" Click="Login_button_Click" Grid.ColumnSpan="2" Grid.Column="1" Grid.Row="2" Margin="160.6,69.6,160.6,44.6" Width="70" Height="25" HorizontalAlignment="Center"/>
 		<TextBox x:Name="AccountBox" TextWrapping="Wrap" Text="201701110203" Grid.Row="2" TextAlignment="Left" Margin="137.6,4.6,137.6,112.6" Grid.Column="1" Grid.ColumnSpan="2" Height="22" Width="122" HorizontalAlignment="Center" BorderThickness="0,0,0,1" VerticalAlignment="Top" />
 		<PasswordBox x:Name="passwordBox" Password="1233211234567" Margin="135,35,135,0" Grid.Column="1" Grid.Row="2" VerticalAlignment="Top" Grid.ColumnSpan="2" Height="22" Width="122" HorizontalAlignment="Center" BorderThickness="0,0,0,1" HorizontalContentAlignment="Left"/>
diff --git a/StormChatWPF/MainWindow.xaml b/StormChatWPF/MainWindow.xaml
index 74d527b..b0f60d8 100644
--- a/StormChatWPF/MainWindow.xaml
+++ b/StormChatWPF/MainWindow.xaml
@@ -5,9 +5,8 @@
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:local="clr-namespace:StormChatWPF"
         mc:Ignorable="d"
-        Title="UserWindow" Height="450" Width="800"
-		
-		>
+        Title="StormChat" Height="450" Width="800"
+		WindowStartupLocation="CenterScreen">
 	<Grid>
 		<Grid.RowDefinitions>
 			<RowDefinition Height="60*"/>
diff --git a/StormChatWPF/MainWindow.xaml.cs b/StormChatWPF/MainWindow.xaml.cs
index 8dcbe1d..427a16a 100644
--- a/StormChatWPF/MainWindow.xaml.cs
+++ b/StormChatWPF/MainWindow.xaml.cs
@@ -48,8 +48,16 @@ namespace StormChatWPF
 
         private void Button_Click(object sender, RoutedEventArgs e)
         {
-            Chat.chat.SendMessage(InputBox.Text,Chat.CurrentContact);
-            InputBox.Text = "";
+            if (Chat.CurrentContact == null)
+            {
+                MessageBox.Show("请选择联系人！");
+                return;
+            }
+            if (InputBox.Text!="")
+            {
+                Chat.chat.SendMessage(InputBox.Text, Chat.CurrentContact);
+                InputBox.Text = "";
+            }
         }
 
         internal void ShowMessage(Message message)
diff --git a/StormChatWPF/Properties/Resources.resx b/StormChatWPF/Properties/Resources.resx
index e42b90e..1af7de1 100644
--- a/StormChatWPF/Properties/Resources.resx
+++ b/StormChatWPF/Properties/Resources.resx
@@ -117,8 +117,4 @@
   <resheader name="writer">
     <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </resheader>
-  <assembly alias="System.Windows.Forms" name="System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
-  <data name="LogFormBackground" type="System.Resources.ResXFileRef, System.Windows.Forms">
-    <value>..\Resources\LogFormBackground.jpg;System.Drawing.Bitmap, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</value>
-  </data>
 </root>
\ No newline at end of file
diff --git a/StormChatWPF/Resources/LogFormBackground.jpg b/StormChatWPF/Resources/LogFormBackground.jpg
new file mode 100644
index 0000000..ea8dcfe
Binary files /dev/null and b/StormChatWPF/Resources/LogFormBackground.jpg differ
diff --git a/StormChatWPF/StormChatWPF.csproj b/StormChatWPF/StormChatWPF.csproj
index c83f885..f3ff667 100644
--- a/StormChatWPF/StormChatWPF.csproj
+++ b/StormChatWPF/StormChatWPF.csproj
@@ -91,10 +91,6 @@
       <DependentUpon>Settings.settings</DependentUpon>
       <DesignTimeSharedInput>True</DesignTimeSharedInput>
     </Compile>
-    <EmbeddedResource Include="Properties\Resources.resx">
-      <Generator>ResXFileCodeGenerator</Generator>
-      <SubType>Designer</SubType>
-    </EmbeddedResource>
     <None Include="Properties\Settings.settings">
       <Generator>SettingsSingleFileGenerator</Generator>
       <LastGenOutput>Settings.Designer.cs</LastGenOutput>
@@ -118,5 +114,10 @@
   <ItemGroup>
     <Resource Include="UI\Resources\聊天气泡.png" />
   </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="Properties\Resources.resx">
+      <SubType>Designer</SubType>
+    </EmbeddedResource>
+  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
 </Project>
\ No newline at end of file
diff --git a/StormChatWPF/UI/ChatBubble.cs b/StormChatWPF/UI/ChatBubble.cs
index 232dbee..1b14f59 100644
--- a/StormChatWPF/UI/ChatBubble.cs
+++ b/StormChatWPF/UI/ChatBubble.cs
@@ -31,7 +31,7 @@ namespace StormChatWPF
         {
             Background = new ImageBrush()
             {
-                ImageSource=new BitmapImage(new Uri("pack://application..../UI/Resource/聊天气泡.png"))
+                ImageSource=new BitmapImage(new Uri("pack://application:,,,/UI/Resources/聊天气泡.png"))
             };
             HorizontalAlignment = alignment;
             text.Text = msg.Text;