C#

bool _dirty = false;
string _filename = null;

void Open(string filename)
{
    // ... stuff to open the file and ...
    _filename = filename;
    _dirty = false;
}

void Save()
{
    if (_filename != null)
        Save(_filename);
    else
        SaveAs();
}

void Save(string filename)
{
    // ... stuff to save the file and...
    _filename = filename;
    _dirty = false;
}

void SaveAs()
{
    if (dlg.ShowDialog() == DialogResult.OK)
        Save(dlg.FileName);
}

void frm_FormClosing(object sender, FormClosingEventArgs e)
{
    if (_dirty)
    {
        DialogResult dr = MessageBox.Show(this, "Do you want to save the changes?",
           "Warning", MessageBoxButtons.YesNoCancel, MessageBoxIcon.Question);

        if (dr == DialogResult.Yes)
            Save();
        else
            e.Cancel = dr == DialogResult.Cancel;
    }
}

private void saveToolStripMenuItem_Click(object sender, EventArgs e)
        {
            SaveFileDialog Save_File = new SaveFileDialog();

            Save_File.Title = "File Saved";
            Save_File.Filter = "Text Files|*.txt|All Files (*.*)|*.*";

            DialogResult dr = Save_File.ShowDialog();
            try
            {
                if (saveFileDialog1.FileName != "")
                {
                    StreamWriter sw = new StreamWriter(Save_File.FileName);
                    sw.Write(txtBox);
                    sw.Close();
                }

                if (dr == DialogResult.OK)
                {
                    StreamWriter sw = new StreamWriter(Save_File.FileName);
                    sw.Write(txtBox.Text);

                    sw.Close();
                }
            }
            catch
            {
                SaveAs();
            }                       
        }

if (saveFileDialog1.FileName != "")
  {
    richTextBox1.SaveFile(saveFileDialog1.FileName, RichTextBoxStreamType.PlainText);
  }
  else
  {
    evtSaveAs_Click(sender, e);
  }

try
{
    using (StreamWriter sw = new StreamWriter(filename))
    {
        // Perform here the write operations
        // If there is an exception here the StreamWriter objet will be disposed
    }
}
catch (Exception ex)
{
    // Handle the exception here: notify user, log, ...
}

private int ReadInPeople()
{
    XmlNodeList nodeList = m_xmlDoc.DocumentElement.ChildNodes;
    foreach (XmlNode PersonNode in nodeList)
    {
        //Form1 myXmlPerson = new Form1();
        Person myXmlPerson = new Person();
        foreach (XmlNode PersonTag in PersonNode.ChildNodes)
        {
            switch (PersonTag.Name)
            {

case "firstName":
    myXmlPerson.FirstName(PersonTag.FirstChild.Value);
    break;
case "lastName":
    myXmlPerson.LastName(PersonTag.FirstChild.Value);
    break;
Ext.....

private string firstName;
private string lastName;
public string MI;
private string address;
public string city;
public string state;
public string zip;
public string time;

public string FirstName
{
    get { return firstName; }
    set { firstName = value; }
}
public string LastName
{
    get { return lastName; }
    set { lastName = value; }
}
public string Address
{
    get { return address; }
    set { address = value; }
}
public string PrintLable()
{
    return firstName + " " + MI + " " + lastName + "\n" + address + "\n" + city + ", " + state + "   " + zip + "\n" + time;
}

static void Main(string[] args)
{
    XDocument x = XDocument.Parse(sXml);
    Reorder(x.FirstNode);
    x.Save(newFileName);
}

private static void Reorder(XNode node)
{
    var kids = (from nd in node.XPathSelectElements("*") orderby nd.Name.LocalName select nd).ToList();
    if (kids.Count>1)
    {
        (node as XElement).ReplaceNodes(kids);
    }
    kids.ForEach(f => Reorder(f));
}

static void Main(string[] args)
{
    string newFileName = "c:\\myfilename.xml";

    XmlDocument docSource = new XmlDocument();
    docSource.LoadXml(XML);
    Reorder(docSource.DocumentElement);
    docSource.Save(newFileName);
}


private static void Reorder(XmlNode node)
{
    SortedList<string, XmlNode> childlist = SortedChildNodes(node);
    node.RemoveAll();
    for (int i = 0; i < childlist.Count; i++)
    {
        Reorder(node.AppendChild(childlist.Values[i]));
    }

}
static SortedList<string, XmlNode> SortedChildNodes(XmlNode node)
{
    SortedList<string, XmlNode> ret = new SortedList<string, XmlNode>();
    for (int i = 0; i < node.ChildNodes.Count; i++)
    {
        string name = node.ChildNodes[i].Name;
        XmlNode nd = node.ChildNodes[i];
        ret.Add(name, nd);
    }
    return ret;
}