String manipulation

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication3
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btnContains_Click(object sender, EventArgs e)
        {
            string ind1 = txtInd1.Text;
            string ind2 = txtInd2.Text;

            if (ind1.Contains(ind2))
            {
                lblUd.Text = "YES";
            }
            else
            {
                lblUd.Text = "NO";
            }
        }

        private void btnInsert_Click(object sender, EventArgs e)
        {
            string ind1 = txtInd1.Text;
            string ind2 = txtInd2.Text;
            int tal = int.Parse(txtTal.Text);

            ind1 = ind1.Insert(tal, ind2);
            lblUd.Text = ind1;
        }
    }
}