QueryString in C#

QueryString in C#:

In this code Query String which is used to Store the UserName and Pass the name from page to other page.

protected void Button1_Click(object sender, EventArgs e)
    {
        string url;
        url = "Detail.aspx?UserName=" + Label3.Text;
        Response.Redirect(url);
    }

Detail.aspx page:

    protected void Page_Load(object sender, EventArgs e)
    {
        Label1.Text = Request.QueryString["UserName"];
    }