how do you get a letter's number position?

Sorry for the trouble, here is my full source code of what I'm working on with comments of what I'm doing.




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 WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

//the word that the person has to guess
string word;

// the letter that the person types to see if the there is a match
string guess;

// lines to show how many characters are missing
string space = "____";



private void Form1_Load(object sender, EventArgs e)
{

}

private void button1_Click(object sender, EventArgs e)
{

//adds a space for each char from the textbox1.
word = textBox1.Text;

foreach (char c in word)
{

// the listview is pretty much the game board, it displays the spaces and letters when correct
listView1.Items.Add(space);
}
}

private void button2_Click(object sender, EventArgs e)
{

// puts any text that the person types into the guess string

guess = textBox2.Text;

// this checks to see if guess has any char comparisons from the word string
foreach(char c2 in word)
{
if (guess.Contains(c2))
{
// I want to see if I can get the letter's line number to see if I can get the listview to
// correctly diplay the letter in the right order.

MessageBox.Show(guess.IndexOf(textBox2.Text).ToString());
}
}
}
}

its pretty much a hangman game. this is just a test but if I can get it right I want to make the game allow users to create their own hangman levels and send the game file to their friends so they can play it.