private void richTextBox1_TextChanged(object sender, EventArgs e) {
            int ln = 0;
            int sel = richTextBox1.SelectionStart;
            foreach (string s in richTextBox1.Lines) {
                int index = commentOut(richTextBox1.Lines[ln]);
                if(richTextBox1.Lines.Length > 0
                    && richTextBox1.Lines[ln].Contains("#")) {
                     richTextBox1.Select(index, richTextBox1.Lines[ln].Length);
                     richTextBox1.SelectionColor = Color.Green;
                     richTextBox1.Select(0, richTextBox1.Lines[ln].Length - index);
                     richTextBox1.SelectionColor = Color.Black;
                     //richTextBox1.Select(sel, 0);
                     richTextBox1.Select(sel, 0);
                    return;
                }
                ln++;
            }
            this.CheckKeyword("while", Color.Purple, 0);
            this.CheckKeyword("if", Color.Green, 0);
        }

        private int commentOut(String line) {
            char[] ar = line.ToCharArray();
            int ln = 0;
            foreach(char s in ar) {
                if(s.ToString().Equals("#")) {
                    break;
                }
                ln++;
            }
            return ln;
        }