C#

string input = "My Name Is Ali";
string[] parts = Regex.Split(input, @"\sIs\s");

string[] parts = input.Split(new string[] { " Is " }, StringSplitOptions.None);

static void Main(string[] args)
        {
            String s = "the bestiality displayed by the main character, Ali, suggests that there is a causality at stake here";
            string pattern = @"\bali\b";
            string replace = "/";
            var s1 = Regex.Replace(s, pattern, replace, RegexOptions.IgnoreCase);
            string[] parts = s1.Split('/');
            for (int i = 0; i < parts.Length; i++)
                Console.WriteLine(parts[i]+ i.ToString());
            Console.ReadLine();

        }

string input = "the bestiality displayed by the main character, Ali, suggests that there is a causality at stake here";
string pattern = @"\bali\b";

string[] parts = Regex.Split(input, pattern, RegexOptions.IgnoreCase);

int index = myEditTextBox.Text.IndexOf(searchForText);
if (index >=0)
    {
    myEditTextBox.SelectionStart = index;
    myEditTextBox.SelectionLength = searchForText.Length;
    myEditTextBox.Focus();
    }

private void cmdFind_Click(object sender, EventArgs e)
       {
           FindClicked(searchTxt.Text);
       }

private void cmdFind_Click(object Sender, EventArgs e)
{
    storedText = searchTxt.Text;
    this.DialogResult = DialogResult.OK;
    Close();
}

private void Form1_Load(object sender, EventArgs e)
       {
           FindForm.FindClicked +=new frmFind.FindClickEventHandler(FindForm_FindClicked);
       }

void FindForm_FindClicked(string strToFind)
{
...
}

private void FindForm_FindClicked(object sender, EventArgs e)
       {
       frmFind finder = sender as frmFind;
       if (finder != null)
           {
           string strSearch = finder.SearchString;  
           ...
           }
       }

public string TextToFind { private set; get;  }

private void btnCancel_Click(object sender, EventArgs e)
{
    this.DialogResult = DialogResult.Cancel;
    this.Close();
}

private void btnFind_Click(object sender, EventArgs e)
{
    TextToFind = textBox1.Text;

    if (String.IsNullOrWhiteSpace(TextToFind))
    {
        MessageBox.Show("Searching on white space makes not sense.");
        return;
    }

    this.DialogResult = DialogResult.OK;
    this.Close();
}

private void Search_Click(object sender, EventArgs e)
{
    if (SearchForm1.ShowDialog() == DialogResult.OK)
    {
        string searchText = SearchForm1.TextToFind;

        // note: case sensitive search here
        int ndx = TheTextBox.Text.IndexOf(searchText);

        if (ndx == -1) return; // nothing found

        TheTextBox.SelectionStart = ndx;
        TheTextBox.SelectionLength = searchText.Length;
    }
}

if (FindForm.ShowDialog() == DialogResult.OK)
               string searchText = FindForm.strToFind;

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;
using System.IO;
using System.Drawing.Printing;

namespace SamsNotePad
{
    public partial class Form1 : Form

    {
        frmFind FindForm = new frmFind();

        public Form1()
        {
            InitializeComponent();
        }
 private void findToolStripMenuItem_Click(object sender, EventArgs e)
        {
           if (FindForm.ShowDialog() == DialogResult.OK)
               string searchText = FindForm.strToFind;

           int ndx = textBox1.Text.IndexOf(searchText);

           if (ndx == -1) return; // nothing found

           textBox1.SelectionStart = ndx;
           textBox1.SelectionLength = searchText.Length;
       }

           // **old Find findForm = new Find(textBox1.Text);
           // **old findForm.Show();


         //   Find findForm = new Find();
         //   findForm.ShowDialog();
            
            

        // if (textBox1.Text.IndexOf(
           // FindForm.Show();
           // FindForm.Focus();
          //  FindForm.ShowDialog();
         //   int index = textBox1.Text.IndexOf(FindForm.strToFind);
         //  if (index >= 0)
         //  {
          //     textBox1.SelectionStart = index;
          //     textBox1.SelectionLength = textBox1.Text.Length;
          //     textBox1.Focus();
           // }}
        

       

        private void findNextToolStripMenuItem_Click(object sender, EventArgs e)
        {
           

        }

        private void replaceToolStripMenuItem_Click(object sender, EventArgs e)
        {

        }

        private void goToToolStripMenuItem_Click(object sender, EventArgs e)
        {

        }

        private void selectAllToolStripMenuItem_Click(object sender, EventArgs e)
        {
            textBox1.SelectAll();
        }

        private void timeDateToolStripMenuItem_Click(object sender, EventArgs e)
        {
            textBox1.Text += DateTime.Now;


        }

        private void statusToolStripMenuItem_Click(object sender, EventArgs e)
        {

        }

        private void wordWrapToolStripMenuItem_Click(object sender, EventArgs e)
        {
            wordWrapToolStripMenuItem.Checked = !(wordWrapToolStripMenuItem.Checked); textBox1.WordWrap = wordWrapToolStripMenuItem.Checked;
        }

        private void fontToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (fontDialog1.ShowDialog() == DialogResult.OK)

                textBox1.Font = fontDialog1.Font; 
        }




        public string strToFind { get; set; }
    }
}

// frmFind (my Find search box)

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 SamsNotePad
{
    public partial class frmFind : Form
    {
        public frmFind()
        {
            InitializeComponent();

        }
        
        public string strToFind {private set; get; }


        private void Cancel_Click(object sender, EventArgs e)
        {
         this.DialogResult = DialogResult.Cancel;
            this.Close();
        }

        private void cmdFind_Click(object sender, EventArgs e)
        {
            strToFind = searchTxt.Text;
            if (string.IsNullOrWhiteSpace(strToFind))
            {
                MessageBox.Show("Please enter search text");
                return;
            }
            this.DialogResult = DialogResult.OK;
            this.Close();
        }

        }
       
        
       











    }