Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index

protected void Deactivate_Click(object sender, EventArgs e)
    {

        LinkButton lnk = sender as LinkButton;
        
        GridViewRow gridrow = lnk.NamingContainer as GridViewRow;
        int userid = Convert.ToInt32(GridView1.DataKeys[gridrow.RowIndex].Value.ToString());
        string username = gridrow.Cells[0].Text;
        con.Open();
        
        OleDbCommand cmd1 = new OleDbCommand("Delete from SlideShowTable1 WHERE U_id=" + userid, con);
        result = cmd1.ExecuteNonQuery();

        con.Close();

        if (result > 0)
        {
            BindEmployeeDetails();
            BindEmployeeDetails1();

            ScriptManager.RegisterStartupScript(this, this.GetType(), "alertmessage", "javascript:alert('" + username + "  Deactivated successfully')", true);

        }

    }