KeyPress ve Error Provider Kullanımı

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 KeyPress
{
public partial class Form1 : Form
{
DateTime dogumTarih = new DateTime();
string ad = "";
string soyad = "";
string tcNo = "";

public Form1()
{
InitializeComponent();
}

private **** btnFormuAc_Click(object sender, EventArgs e)
{
formerrorprovider f = new formerrorprovider();
f.BunuAcanform = this;
f.Show();
this.Hide();
}

private **** btnKaydet_Click(object sender, EventArgs e)
{
ad = txtAd.Text;
soyad = txtSoyad.Text;
dogumTarih = DateTime.Parse(txtDtarih.Text);
tcNo = txtTCNO.Text;
}

private **** txtAd_KeyPress(object sender, KeyPressEventArgs e)
{

if (char.IsNumber(e.KeyChar) && e.KeyChar != '\b')
{
e.Handled = true;
}
}

private **** txtSoyad_KeyPress(object sender, KeyPressEventArgs e)
{
if (char.IsNumber(e.KeyChar) && e.KeyChar != '\b')
{
e.Handled = true;
}
}

private **** txtDtarih_KeyPress(object sender, KeyPressEventArgs e)
{
if (!char.IsNumber(e.KeyChar) && e.KeyChar != '.' && e.KeyChar != '\b')
e.Handled = true;
}

private **** txtTCNO_KeyPress(object sender, KeyPressEventArgs e)
{
if (!char.IsNumber(e.KeyChar) && e.KeyChar != '\b')
e.Handled = true;
}
}
}







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 KeyPress
{
public partial class formerrorprovider : Form
{
public formerrorprovider()
{
InitializeComponent();
}

public Form1 BunuAcanform = null;

private **** txtkod_Validating(object sender, CancelEventArgs e)
{
if (string.IsNullOrEmpty(txtkod.Text) || txtkod.Text.Trim().Equals(""))
return;
if (!char.IsLetter(txtkod.Text[0]) || txtkod.Text.Length != 5)
{
errorProvider1.SetError(txtkod, "Firma kodu 5 karakterden oluşmalı ve ilk karakter harf olmalı");
e.Cancel=true;
}
else
errorProvider1.Clear();
}

private **** btnKaydetIlerle_Click(object sender, EventArgs e)
{
MessageBox.Show("Diger bölümü hazır olmadıgından ilerleyemeyeceksiniz...");
}


private **** frmerrorprovider_FormClosed(object sender, FormClosedEventArgs e)
{
BunuAcanform.Show();
}
}
}