List<string> myLines = new List<string>();
            using (StringReader r2 = new StringReader(txtMain.Text))
            {
                string txtLine;
                while ((txtLine = r2.ReadLine()) != null)
                {
                    myLines.Add(txtLine);
                }
            }
            myLines.Sort();
            using (StringWriter sw = new StringWriter())
            {
                foreach (string s in myLines)
                {
                    sw.WriteLine(s);
                }
                txtMain.Text = sw.ToString();
            }

            List<String> lines = textBox1.Text.Split('\n').ToList();
            lines.Sort();
            textBox2.Text = String.Join("\n", lines.ToArray());

 try
            {
//create some string lists to hold your lines
 
                List<string> mySortLines = new List<string>();
                List<string> mySortLines2 = new List<string>();
 
                //declare a variable to hold the lengh of the first line
                int int4length = 0;
                int X = 0;
 
//create a string reader to read in the lines of text from RTB (txtMain)
                using (StringReader r3 = new StringReader(txtMain.Text))
                {
//create some vars to hold the selected text (on the first line) to show what column to sort by.
 
                    string txtSortLine;
                    int txtSelectedStart = txtMain.SelectionStart;
                    int txtSelectedLength = txtMain.SelectionLength;
                    string txtSortcharacter = string.Empty;
//if no text is selected, abort and show error message
                    if (txtSelectedLength == 0)
                    {
                        MessageBox.Show("you must select characters from the first line of text", "Sort Error", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
                        return;
                    }
//do the magic, create loop to run each line of text
                    while ((txtSortLine = r3.ReadLine()) != null)
                    {
 
                        //set int4lenght var
 
                        if (X < 1)
                        {
                            int4length = txtSortLine.Length;
                            X++;
 
                            //check if text is selected on the first line
                            if (int4length < txtSelectedStart)
                            {
                                MessageBox.Show("you must select characters from the first line of text", "Sort Error", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
                                return;
                            }
                        }
 
                        //check if line contains entire selected coulmns 
                        if (txtSortLine.Length >= (txtSelectedStart + txtSelectedLength))
                        {
 
                            mySortLines.Add(txtSortLine);
                            mySortLines2.Add(txtSortLine.Substring(txtSelectedStart, txtSelectedLength));
 
 
 
                        }
                        //check if lines are shorter than selected columns if so sort as blank
                        if (txtSelectedStart + 1 > txtSortLine.Length)
                        {
                            mySortLines.Add(txtSortLine);
                            mySortLines2.Add("");
                                  ProgressBar.Value += 1;
                        }
                        //need to sort for lines that contain part of selected columns
                        if (txtSortLine.Length >= (txtSelectedStart + 1) && txtSortLine.Length < (txtSelectedStart + txtSelectedLength))
                        {
                            mySortLines.Add(txtSortLine);
                            mySortLines2.Add(txtSortLine.Substring(txtSelectedStart, txtSortLine.Length - (txtSelectedStart)));
                                  ProgressBar.Value += 1;
                        }
 
 
                    }
 
//convert lists to arrays, then sort lines, by column keys
                    string[] sortArray = mySortLines.ToArray();
                    string[] sortArray2 = mySortLines2.ToArray();
                    Array.Sort(sortArray2, sortArray);
 
//little cleaning
                    mySortLines = null;
                    mySortLines2 = null;
                    sortArray2 = null;
//create a string writer and put the sorted text back to the RTB
                    using (StringWriter sw2 = new StringWriter())
                    {
                        foreach (string s in sortArray)
                        {
                            sw2.WriteLine(s);
                        }
                        txtMain.Text = sw2.ToString();
                        txtMain.Modified = true;
 
 
                        sortArray = null;
 
 
                    }
 
 
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message.ToString(), "Error");
            }
        }