Login failed. The login is from an untrusted domain and cannot be used with Windows authentication

My webpages are on secured server (https), and I am trying to connect the SQL Server 2008 Database, which is normal server. I am writing connectionstring on page itself, not in web.config file. And I am getting following error:-

System.Data.SqlClient.SqlException: Login failed.
The login is from an untrusted domain and cannot be used with Windows authentication.

Please help, how can I connect it, does I have to make some webservices for it.

my code is as below:

public void FillCity()
{
    SqlConnection con = new SqlConnection();
    con.ConnectionString = "integrated security=SSPI;data source=dev-fcb; user id=sa;password=password;" 
    +"persist security info=False;database=mediapro";
    con.Open();
    SqlDataAdapter da = new SqlDataAdapter();
    da.SelectCommand = new SqlCommand("select * from StateCityMaster where IsActive='1' order by CityName", con);
    DataSet ds = new DataSet();
    da.Fill(ds);
    string CityName = string.Empty;
    if (ds.Tables[0].Rows.Count > 0)
    {
        CityName = ds.Tables[0].Rows[0]["CityName"].ToString();
    }
    DataSet dset = new DataSet();
    da.Fill(dset);
    if (dset.Tables[0].Rows.Count > 0)
    {
        drpCity.DataSource = dset;
        drpCity.DataTextField = "CityName";
        drpCity.DataValueField = "CityName";
        drpCity.DataBind();
    }
    drpCity.Items.Insert(0, new ListItem("--Select--", "0"));
    con.Close();
}