private void button1_Click(object sender, EventArgs e)

        {
            int parsedValue;
            if (int.TryParse(Alter.Text, out parsedValue)&& int.TryParse(Zeit.Text, out parsedValue)&& Adresse.Text!="" && Alter.Text != "" && Geschlecht.Text != "" && Adresse.Text != "Zeit" && Bandname.Text != "" && Name.Text !="")
            {

                int Kosten;
                if (checkBox1.Checked)