Hi,
You should Disable auto column generation of the Gridview.
Either modify Gridview property in designer (AutoGenerateColumns="False")
for Example
<asp:GridView AutoGenerateColumns="False" ...>
or in the code editor
GridView1.AutoGenerateColumns=False ;
GridView1.DataBind();
protected void Page_Load(object sender, EventArgs e)
{
conn = new SqlConnection("initial catalog=shikhar;integrated security=yes;server=SHAMMI\\SQLEXPRESS");
da = new SqlDataAdapter("Select id,name,city from rrr", conn);
dt = new DataTable();
da.Fill(dt);
GridView1.DataSource = dt;
GridView1.AutoGenerateColumns = false ;
GridView1.DataBind();
}