How to connect to MySql database on internet web server not on localhost using c#?

i have a web server on internet i am using php/mysql. for my website, now i want to connect to my mysql database on my webserver using my c# windows form application so that i will be able to view,create, update, delete the data on mysql database on webserver, i want to user same database for website and my desktop application. i want any one having my desktop application would be able to update my database on my webserver(i mean not only form some specific ip). Here is my code when i try to run it shows error "Unable to connect to any of specified MySQL hosts." can any one Guide me how to do it. Thanks. The following code is working fine for localhost but not working for web-server which is on internet.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using MySql.Data.MySqlClient; // for mysql

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            string con_str = "SERVER=fdb4.biz.nf;Port=3306;DATABASE=1558711_zee;UID=1558711_zee;PASSWORD=multan321;compress=true;";


            MySqlConnection connection = new MySqlConnection(con_str);

            try {
                connection.Open();
                MySqlCommand cmd = connection.CreateCommand();
                cmd.CommandText = "SELECT * FROM  zeetable";
                MySqlDataAdapter mda = new MySqlDataAdapter(cmd);
                DataSet mds = new DataSet();
                mda.Fill(mds);
                dataGridView1.DataSource = mds.Tables[0].DefaultView;
            }
            catch(MySqlException ex){

                MessageBox.Show(ex.Message);
            }
        }

        }
    }