private void textBox1_TextChanged(object sender, EventArgs e)
        {
            BigInteger exp;

            BigInteger.TryParse(textBox1.Text, out exp);
            textBox3.Text = "" + CalculateExp.GetExperienceFromLevel(exp);
        }
        private void textBox2_TextChanged(object sender, EventArgs e)
        {
            BigInteger exp;

            BigInteger.TryParse(textBox2.Text, out exp);
            BigInteger expToLevel = CalculateExp.GetLevelFromExperience(exp);
            BigInteger remainder  = exp - CalculateExp.GetExperienceFromLevel(expToLevel);

            Debug.WriteLine(remainder);
            textBox4.Text = "" + expToLevel;
            textBox5.Text = "" + CalculateExp.getExpUntilNextLevel(exp, expToLevel + 1);
        }