private void DencryptionButton_Click(object sender, EventArgs e)
{
var input = ClearText(InputTextBox.Text);
var key = ClearTextWithError(DecryptionKeyTextBox.Text);
if (!string.IsNullOrEmpty(input) && !string.IsNullOrEmpty(key))
{
ResultTextBox.Text = TextWithSpaces(cipher.Decrypting(input, key));
}
}