HI This will help you copy and paste it
SqlConnection con = new SqlConnection("Connection");
SqlCommand cmd = new SqlCommand("select pwd,userName from LoginTable",con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(da);
if (txtPassword.Text == dt.Rows[0]["pwd"].ToString() && txtUserName.Text == dt.Rows[0]["userName"].ToString())
{
Response.Redirect("abc.aspx");
}
else
{
}