fire GridView1_RowCommand more then once

I'm new to asp, I have a tabcontainer with 1 tabpanel created at design time.tabpanel contained a gridview filled with usernames. with code below, if I click on detail button beside any username I got 4 new tabs created with different info, and I can browse between these tabs no problem. but if I go back to my main tab where all username and click a different user, nothing happen. any idea on how to solve this problem ? thank you

<form id="form1" runat="server"><div id="divGrid">                                                          <asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager><asp:UpdatePanel ID="UpdatePanel1" runat="server"><ContentTemplate><cc1:TabContainer AutoPostBack="true"  ID="TabContainer1" runat="server" Height="700" ScrollBars="Both"><cc1:TabPanel ID="MenuAddTwoNums" HeaderText="User" runat="server"><ContentTemplate><asp:PlaceHolder ID="UC1Holder" runat="server"><ContentTemplate><asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"  
                                Font-Bold="False" Font-Size="Small" GridLines="Horizontal" style="width:50%"  
                                HorizontalAlign="Left" OnRowCommand="GridView1_RowCommand" Height="630px" ><AlternatingRowStyle Height="10px" /><Columns><asp:BoundField DataField="name" HeaderText="Name" /><asp:BoundField DataField="SamAccountName" HeaderText="Username" /><asp:BoundField><ItemStyle Width="20px" /></asp:BoundField><asp:BoundField /><asp:BoundField /><asp:ButtonField ButtonType="Image" CommandName="Details" 
                                        ImageUrl="~/Resources/Images/view.gif" Text="Details"><ItemStyle Width="30px" /></asp:ButtonField></Columns><EditRowStyle BackColor="#99CCFF" BorderStyle="None" Font-Size="Small" 
                                    ForeColor="Black" Height="30px" HorizontalAlign="Left" /><HeaderStyle BackColor="White" BorderColor="#CCCCCC" Font-Size="Small" 
                                    HorizontalAlign="Left" /><RowStyle BackColor="White" BorderColor="#CCCCCC" Font-Size="Small" 
                                    HorizontalAlign="Left" /><SelectedRowStyle BackColor="White" BorderColor="#CCCCCC" /></asp:GridView></ContentTemplate></asp:PlaceHolder></ContentTemplate></cc1:TabPanel></cc1:TabContainer></ContentTemplate></asp:UpdatePanel>
   protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
    {

        if (IsPostBack)
        {
            if (e.CommandName == "Details")
            {


                List<string> result1 = new List<string>();
                   List<string> UserAP = new List<string>();
                List<string> UserGROUP = new List<string>();
                List<string> UserSHARED = new List<string>();
                int row = int.Parse(e.CommandArgument.ToString());
                item = GridView1.Rows[row].Cells[1].Text;
                DirectoryEntry de = new DirectoryEntry();
                de.Path = "LDAP://xx.com";
                DirectorySearcher objADSearcher = new DirectorySearcher(de);
                de.AuthenticationType = AuthenticationTypes.Secure;

                objADSearcher.SearchRoot = de;
                objADSearcher.Filter = "(SAMAccountName=" + item + ")";
                SearchResult results = objADSearcher.FindOne();
                if (results.ToString() != "")
                {

                    int flags = Convert.ToInt32(results.Properties["userAccountControl"][0].ToString());
                    //for reference results.Properties["userAccountControl"][0].ToString().Equals("514");

                    if (Convert.ToBoolean(flags & 0x0002))
                    {
                        Response.Write("<script> alert ('" + "Account Disabled  + "') </script>");


                    }
                    else
                    {


                        WindowsIdentity wi = new WindowsIdentity(item);


                        foreach (IdentityReference group in wi.Groups)
                        {
                            try
                            {

                                result1.Add(group.Translate(typeof(NTAccount)).ToString());
                                result1.Sort();

                            }
                            catch (Exception ex)
                            { }
                        }
                AjaxControlToolkit.TabPanel apptab = new AjaxControlToolkit.TabPanel();

                        apptab.HeaderText = item + " " + "Application";
                        apptab.ID = "tab1";
                        AjaxControlToolkit.TabPanel sharedtab = new AjaxControlToolkit.TabPanel();

                        sharedtab.HeaderText = item + " " + "SharedCommon";
                        sharedtab.ID = "tab2";
                        AjaxControlToolkit.TabPanel grouptab = new AjaxControlToolkit.TabPanel();

                        grouptab.HeaderText = item + " " + "Internet/RAS";
                        grouptab.ID = "tab3";
                        AjaxControlToolkit.TabPanel idtab = new AjaxControlToolkit.TabPanel();

                        idtab.HeaderText = item + " " + "Info";
                        idtab.ID = "tab4";


                        TabContainer1.Tabs.Add(grouptab);
                        TabContainer1.Tabs.Add(apptab);
                        TabContainer1.Tabs.Add(sharedtab);
                        TabContainer1.Tabs.Add(idtab);