private void button3_Click(object sender, EventArgs e) { removeLabel = true; removeLabels(); try { mySeconds = Convert.ToInt32(textBox3.Text); timerEvent.setTimer(mySeconds); } catch (FormatException e1) { System.Windows.Forms.MessageBox.Show("Input is not a valid number(int)."); textBox3.Text = ""; } catch (OverflowException e1) { textBox3.Text = ""; System.Windows.Forms.MessageBox.Show("This number doesn't fit in Int32"); } }