Remove the security credentials from a connection string

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;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        string m_DatabaseConnectionString = "Data Source=MYHAPPYHAPPYDB\\SQLEXPRESS;Initial Catalog=JoyJoy;user=sa;password=W@nk3r";

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string message = "Blah blah blah [" + m_DatabaseConnectionString + "] blah";

            string tmpStr = RemoveConnectionStringSecurity(message);

            MessageBox.Show(message + "\r\n\r\n becomes \r\n\r\n" + tmpStr);
        }

        private string RemoveConnectionStringSecurity(string inString)
        {
            string[] securityQualifiers = new string[] { "user", "uid", "password", "pwd" };
            string retStr = m_DatabaseConnectionString;

            foreach (string qualifier in securityQualifiers)
            {
                if (retStr.IndexOf(qualifier + "=") > 0)
                {
                    // Remove Security Qualifier
                    try
                    {
                        retStr = retStr.Substring(0, retStr.ToLower().IndexOf(qualifier + "=") + qualifier.Length + 1)
                            + "*HIDDEN*"
                            + retStr.Substring
                            (
                                retStr.ToLower().IndexOf(qualifier + "="),
                                retStr.Length - retStr.ToLower().IndexOf(qualifier + "=")
                            ).Substring
                                (
                                    retStr.Substring
                                    (
                                        retStr.ToLower().IndexOf(qualifier + "="),
                                        retStr.Length - retStr.ToLower().IndexOf(qualifier + "=")
                                    ).IndexOf(";")
                                );
                    }
                    catch
                    {
                    // Last element and no terminating ';'
                        retStr = retStr.Substring(0, retStr.ToLower().IndexOf(qualifier + "=") + qualifier.Length + 1)
                            + "*HIDDEN*";
                    }
                }
            }

            return inString.Replace(m_DatabaseConnectionString, retStr);
        }

    }
}