Progress bar not working with update panel in side gridview

Progress bar not working with update panel in side gridview when we click on check box which is inside gridview..

<%----%>

AutoPostBack="true" />

<%--

AutoPostBack="true" />

--%>

protected void Page_Load(object sender, EventArgs e)

{

if (!IsPostBack)

{

BindGridview();

}

protected void Unnamed1_CheckedChanged(object sender, EventArgs e)

{

// Page.ClientScript.RegisterStartupScript(this.GetType(), "Hide", "Hide();", true);

}

protected void BindGridview()

{

SqlConnection con = new SqlConnection("Data Source=BRIJESH\\RRIJESH;Initial Catalog=Test;Integrated Security=True");

con.Open();

SqlCommand cmd = new SqlCommand("select * from tbl_emp", con);

SqlDataAdapter da = new SqlDataAdapter(cmd);

DataSet ds = new DataSet();

da.Fill(ds);

grid1.DataSource = ds;

grid1.DataBind();

}