Make a session to remember what value user have insert in textbox

<asp:Panel ID="Panel_visfrugt" runat="server">
        <table border="1">
            <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>" SelectCommand="SELECT * FROM [frugt]"></asp:SqlDataSource>
            <tr>
                <td>Antal</td>
                <td><asp:Label ID="Label1" runat="server" Text=""></asp:Label></td>
            </tr>
            <asp:Repeater ID="Repeater1" runat="server" DataSourceID="SqlDataSource1" OnItemCommand="Repeater1_ItemCommand">
                <ItemTemplate>

            
            <tr>
                <td><%#Eval("frugt_navn") %></td>
                <td><asp:TextBox ID="txtbox1" runat="server" Width="30"></asp:TextBox></td>
                
            </tr>
           
    </ItemTemplate>
            </asp:Repeater>
        </table>
    
    <asp:Button ID="Button1" runat="server" Text="Læg i kurv" OnClick="Button1_Click1" /> 
    </asp:Panel>
        <asp:Panel ID="Panel_vis" runat="server" >
            
            <h4>De har nu lagt disse ting i kurven</h4>
            <asp:Repeater ID="Repeater2" runat="server" DataSourceID="SqlDataSource1">
                <ItemTemplate>

              <%#Eval("frugt_navn") %>

            
            <asp:Label ID="Label_vis" runat="server" Text="Label"></asp:Label>
  </ItemTemplate>
            </asp:Repeater>
        </asp:Panel>
        <asp:Button ID="Button2" runat="server" Text="slet session" OnClick="Button2_Click" />

 private int Value = 0;
    protected void Page_Load(object sender, EventArgs e)
    {
       
        Panel_visfrugt.Visible = true;
        Panel_vis.Visible = false;
        
       
    }
protected void Button1_Click1(object sender, EventArgs e)
    {
        foreach (RepeaterItem item in Repeater1.Items)
        {
            if (item.ItemType == ListItemType.Item || item.ItemType == ListItemType.AlternatingItem)
            {
                TextBox Textbox_antal = item.FindControl("txtbox1") as TextBox;

                if (Textbox_antal != null)
                {
                    Textbox_antal.Text = "0";
                }
                
                Value = Convert.ToInt32(Value + int.Parse(Textbox_antal.Text));
                Session["frugt"] = Value;

                if (Value != 7)
                {
                    Label1.Text = "Der er 7 nu";
                    Panel_visfrugt.Visible = false;
                    Panel_vis.Visible = true;

                }
                else if (Value > 7)
                {
                    Label1.Text = "Det er kun muligt at bestille 7 stk frugt";
                    
                }
            }
        }
        if (Session["frugt"] != null)
        {
            Label_vis.Text = Convert.ToString(Session["frugt"]);
        }
          
              
    }



    protected void Button2_Click(object sender, EventArgs e)
    {
        Session.Abandon();
        Response.Redirect("Default.aspx");
    }