diff --git a/src/AdvancedCalculator/Views/MainView.axaml b/src/AdvancedCalculator/Views/MainView.axaml
index 04573d9..2f8134c 100644
--- a/src/AdvancedCalculator/Views/MainView.axaml
+++ b/src/AdvancedCalculator/Views/MainView.axaml
@@ -36,7 +36,7 @@
 								<Button x:DataType="vm:MainViewModel"
 										DataContext="{Binding #Root.DataContext}"
 										Command="{Binding InsertVariableCommand}"
-										CommandParameter="{Binding $parent[ListBoxItem].DataContext}"
+                                            CommandParameter="{Binding $parent[ListBoxItem].DataContext.FunctionName}"
 										Background="Transparent" BorderThickness="0" Padding="8" MinHeight="44"
 										AutomationProperties.Name="Insert variable">
 									<Grid ColumnDefinitions="Auto,*,Auto"
@@ -120,7 +120,7 @@
 													<Button x:DataType="vm:MainViewModel"
 															DataContext="{Binding #Root.DataContext}"
 															Command="{Binding InsertFunctionCommand}"
-															CommandParameter="{Binding $parent[ListBoxItem].DataContext}"
+                            CommandParameter="{Binding $parent[ListBoxItem].DataContext.VariableName}"
 															Background="Transparent" BorderThickness="0" Padding="8" MinHeight="44"
 															AutomationProperties.Name="Insert function">
 														<StackPanel Spacing="8"
@@ -153,9 +153,13 @@
 						<TextBlock FontFamily="{StaticResource MDI}" Text="{x:Static m:IconFont.Function}" />
 					</Button>
 
-					<TextBox Grid.Column="2" Text="{Binding InputText, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" MinHeight="44"
-							 AutomationProperties.Name="Expression input"
-							 Watermark="Type an expression (e.g., 2 + 2)"/>
+                    <TextBox Grid.Column="2" Text="{Binding InputText, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" MinHeight="44"
+                             AutomationProperties.Name="Expression input"
+                             Watermark="Type an expression (e.g., 2 + 2)">
+                        <InputElement.KeyBindings>
+                            <KeyBinding Gesture="Enter" Command="{Binding SubmitCommand}" />
+                        </InputElement.KeyBindings>
+                    </TextBox>
 
 					<!-- Explicit evaluate button for touch -->
 					<Button Grid.Column="3" Command="{Binding SubmitCommand}" MinHeight="44" Padding="16,8"