I am trying to make a simple library database. I list the search results in a gridview, then i have a textbox and a button, user enters the isbn and clicks loan button. Then, if there is enough number of items (itemNumber>0) it is loaned by user. Here is the screenshot of user interface:

enter image description here

My question is, when user clicks loan button the loan may or may not be succesful. In both cases, i print a message indicating whether loan is succesful or not, and i also want the updated gridview to be displayed. The problem is, after pressing the loan button the gridview disappears and i just see the textbox, button and the message on the screen. How can i show the updated version of gridview after pressing loan button?

Here is the code file:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="SearchResults.aspx.cs" Inherits="Pages_SearchResults" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>

</div>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" 
    DataKeyNames="ISBN" DataSourceID="SqlDataSource1" 
    onselectedindexchanged="GridView1_SelectedIndexChanged" 
    onrowcommand="GridView1_RowCommand">
    <Columns>
        <asp:BoundField DataField="Title" HeaderText="Title" SortExpression="Title" />
        <asp:BoundField DataField="ISBN" HeaderText="ISBN" ReadOnly="True" 
            SortExpression="ISBN" />
        <asp:BoundField DataField="AuthorName" HeaderText="AuthorName" 
            SortExpression="AuthorName" />
        <asp:BoundField DataField="AuthorlName" HeaderText="AuthorlName" 
            SortExpression
asp.net database gridview
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