Is Numeric Validation

 public bool IsNumeric(string text)
        {
            bool isNumeric = false;
            foreach (char c in text)
            {
                if (c < '0' || c > '9')
                {
                    isNumeric = false;
                }
                else
                {
                    isNumeric = true;
                }
            }
            return isNumeric;
        }