private void TextBox1_KeyPress(object sender, KeyPressEventArgs e) {if (!Char.IsLetter(e.KeyChar) && !Char.IsControl(e.KeyChar))e.Handled = true; }

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
             if(e.Keychar=='\b')
       {
             e.Handled=false;
        }
}