private void btnClearFrequencies_Click(object sender, EventArgs e)
{
TextBox[] frequencyTextBoxes = new TextBox[] {
txtLettersLower, txtLettersUpper, txtDigits, txtDigitSymbols,
txtEasySymbols, txtEasySymbolsShift, txtHardSymbols, txtHardSymbolsShift };
if (frequencyTextBoxes.Where(tb => !string.IsNullOrEmpty(tb.Text) && readInt(tb) != 0).Count() > 0)
{
DialogResult dialogResult = MessageBox.Show("Are you sure you want to clear frequency TextBoxes?", "Question",
MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button1);
if (dialogResult == DialogResult.Yes)
foreach (TextBox textBox in frequencyTextBoxes)
textBox.Text = "";
}
}