sql/wpf_connection3/Windows/EnterMinCostForAgentWindow.xaml

<Window x:Class="wpf_connection3.Windows.EnterMinCostForAgentWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:wpf_connection3.Windows"
        mc:Ignorable="d"
        Title="МИНИМАЛЬНАЯ ЦЕНА" Height="450" Width="800"

        Background="White">
   
    <Grid>
        <StackPanel
            Background="White"
            Height="1200"
    Orientation="Vertical" Margin="0,50,0,0">

            <TextBox
        Name="CostTextBox"
        />
            <Button
                Height="88"
                Background="PeachPuff"
        Content="Изменить"
                Click="Button_Click"
                />
        </StackPanel>
    </Grid>
</Window>