Is AlphaNumeric Validation

 public  bool IsAlphaNumeric(string stringValue)
        {
            bool m_result = true;
            string m_strValue = stringValue.Trim();

            System.Text.RegularExpressions.Regex rx = new System.Text.RegularExpressions.Regex(@"^[a-zA-Z0-9]*$");
            if (!rx.IsMatch(m_strValue))
            {
                m_result = false;
            }
            return m_result;
        }