private void txtquanwen_TextChanged(object sender, EventArgs e)
        {
            string putter = "[^%&',;=?$\x22]+";
            if (!CheckIsFormat(putter, this.txtquanwen.Text))
            {
                if (txtquanwen.Text == "")
                {
                    txtqwbeforevalue = "";
                }
                else
                {
                    txtquanwen.Text = txtqwbeforevalue;
                }
            }
            else
            {

                txtqwbeforevalue = this.txtquanwen.Text;
            }
        }

        public static bool CheckIsFormat(string strRegex, string strValue)
        {
            if (strValue != null && strValue.Trim() != "")
            {
                Regex re = new Regex(strRegex);
                if (re.IsMatch(strValue))
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            return false;
        }