maintain child windows while leaving page

You can open child window from parent window using window.open method and you can switch between Parent and child window.

here is the script:

<form id="form1" runat="server">
    <div>
        <asp:Button Text="OpenChild" OnClientClick="OpenWindow();return false;" runat="server" />
    </div>
    <script type="text/javascript">
        function OpenWindow() {
            window.open('MainPage.aspx', 'Hello', 'height=100,left = 490,top = 262');
        }
    </script>
    </form>