public class AjaxMethod www.companysz.com
{
    public AjaxMethod()
    {
        //
        //TODO: 在此處添加構造函數邏輯
        //
    }
    [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.Read)]
    public static string GetCardMoney(string cardNo,string cardPwd)
    {
        string mConn = IConfiguration.getParameter("connectString");
        IDBOSQL.IDBO dbo = IDBOSQL.IDBO.getIDBO(mConn);
        dbo.openDatabase();
        DataSet ds = dbo.executeSelectSql("select Card_Money,Service_Discount,Good_Discount from Table_CardInfo join Dic_CardType on Table_CardInfo.CardType_ID= Dic_CardType.CardType_ID where Card_NO='"+cardNo+"' and Card_Pwd= '"+cardPwd+"'and card_Status='正常'");
        DataTable dt = ds.Tables[0];
        string  money = dt.Rows[0][0].ToString();
        string service_discount = dt.Rows[0][1].ToString();
    string good_discount = dt.Rows[0][2].ToString();
        dbo.closeDatabase();
       return money+","+service_discount+','+good_discount;//此處返回一個多個值拼接成的字符串
    }
}

moneydiscount= AjaxMethod.GetCardMoney(card, pwd).value;
moneydiscount//是一個多個值拼接成的字符串，要獲取多個值的話，可以把該字符串轉換為一個數組，然后去訪問。
arr=moneydiscount.split(",");        //這樣的話可以很方便的使用Ajax返回多個值。

document.getElementById("txtCard_Money1").value=arr[0];

<httpHandlers>
<add verb="POST,GET" path="ajax/*.ashx" type="Ajax.PageHandlerFactory, Ajax"/>
</httpHandlers>