errorProvider

Question

I created an errorProvider on an windows application to validate text boxes. It works great if I enter something values out side an int range. I cannot make it work if the box is blank or if I enter characters in the text box. How can errorProvider validate under these two conditions? private void buttonAccept_Click(object sender, System.EventArgs e) { int pick, totalPick, max; max = int.Parse(textBoxMax.Text); totalPick = int.Parse(textBoxPick.Text); pick = int.Parse(textBoxEnterNumber.Text); if (countNumber>=totalPick) { errorProvider.SetError(textBoxEnterNumber, "You have picked " + totalPick + " the numbers."); } else if (pick<1 || pick>max) { errorProvider.SetError(textBoxEnterNumber, "You must enter a number from 1 to " + max + "."); } //This does not work else if (textBoxEnterNumber.Text == "") { errorProvider.SetError(textBoxEnterNumber, "You must enter a number from 1 to " + max + "."); } else { countNumber++; numbers.Add(pick); textBoxEnterNumber.Clear(); textBoxMessages.Text += "Number" + (countNumber) + ": " + pick.ToString()+"\r\n"; errorProvider.SetError(textBoxEnterNumber, ""); } }