Display Label values in JavaScript Popup Window using Session in ASP.Net

Here I have created sample that shows the popup window displaying the Customer Details

Default.aspx

HTML

<asp:Button ID="btnShowPopup" OnClick="ShowDetails" Text="ShowDetails" runat="server" />
<table border="0" cellpadding="0" cellspacing="0">
    <tr>
        <td>
            <asp:Label Text="Customer ID" runat="server" />
        </td>
        <td>
            <asp:Label ID="lblCustomerId" runat="server" />
        </td>
    </tr>
    <tr>
        <td>
            <asp:Label Text="Name" runat="server" />
        </td>
        <td>
            <asp:Label ID="lblName" runat="server" />
        </td>
    </tr>
    <tr>
        <td>
            <asp:Label Text="Country" runat="server" />
        </td>
        <td>
            <asp:Label ID="lblCountry" runat="server" />
        </td>
    </tr>
</table>

Code

protected void Page_Load(object sender, EventArgs e)
{
    Session["CustomerId"] = this.lblCustomerId.Text = "1";
    Session["Name"] = this.lblName.Text = "Peter";
    Session["Country"] = this.lblCountry.Text = "England";
}

protected void ShowDetails(object sender, EventArgs e)
{
    string url = "PopupPage.aspx";
    string popupWindow = "window.open('" + url + "','popup','toolbar=no,scrollbars=no,location=no,statusbar=no,menubar=no,resizable=0,width=100,height=100,left = 490,top=300')";
    ClientScript.RegisterClientScriptBlock(this.GetType(), "popup", popupWindow, true);
}

PopupPage.aspx

HTML

<table border="0" cellpadding="0" cellspacing="0">
    <tr>
        <td>
            <asp:Label Text="Customer ID" runat="server" />
        </td>
        <td>
            <asp:Label ID="lblCustomerId" runat="server" />
        </td>
    </tr>
    <tr>
        <td>
            <asp:Label Text="Name" runat="server" />
        </td>
        <td>
            <asp:Label ID="lblName" runat="server" />
        </td>
    </tr>
    <tr>
        <td>
            <asp:Label Text="Country" runat="server" />
        </td>
        <td>
            <asp:Label ID="lblCountry" runat="server" />
        </td>
    </tr>
</table>

Code

protected void Page_Load(object sender, EventArgs e)
{
    this.lblCustomerId.Text = Session["CustomerId"].ToString();
    this.lblName.Text = Session["Name"].ToString();
    this.lblCountry.Text = Session["Country"].ToString();
}

Screenshot