how to use savedialogbox in c#

SaveFileDialog saveFile1 = new SaveFileDialog();
            saveFile1.DefaultExt = "*.txt";
            saveFile1.Filter = "RTF Files|*.rtf|TXT Files|*.txt";//you may add/take away the type you want to save the file as...
            saveFile1.FileName = "please select a file extension at the bottom BEFORE saving.";//just what the input box for the file name will say.. you can change this too, to fit your needs.
            if (saveFile1.ShowDialog() == System.Windows.Forms.DialogResult.OK &&
               saveFile1.FileName.Length > 0)
            {
                //here you select what you want to save. for example the text of a richtextbox...
                richtextBox1.SaveFile(saveFile1.FileName, RichTextBoxStreamType.PlainText);
            }