<xsl:value-of select="contract/@balance"/>

<xsl:template name="ContractStatus">
   
   Текущий статус: <b><xsl:value-of select="/data/@statusstr"/></b>.

Остаток вашего баланса опустился ниже допустимого уровня и составляет <xsl:value-of select="contract/@balance"/>.

<xsl:value-of select="/data/@statusstr"/>

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
   xmlns:common="http://common.bitel.ru"
   xmlns:utils="ru.bitel.common.Utils"

   xmlns:fo="http://www.w3.org/1999/XSL/Format"
   xmlns:svg="http://www.w3.org/2000/svg"
   xmlns:xalan="http://xml.apache.org/xalan"
   xmlns:sql="bitel.billing.server.util.exslt.SQLQuery">

<xsl:variable name="query">SELECT (`summa1`-`summa3`)+`summa2` as `balance` FROM `contract_balance` WHERE `mm` = (SELECT MAX(`mm`) FROM `contract_balance` WHERE `yy` = (SELECT MAX(`yy`) FROM `contract_balance`)) AND `cid` = '<xsl:value-of select="$CONTRACT_ID"/>'</xsl:variable>
<xsl:variable name="contracts" select="sql:select($query)"/>

[code]<xsl:variable name="balance"><xsl:value-of select="$contracts/row/@balance"/></xsl:variable>[/code]

            <!-- title  -->
            <div class="pageTitle">
               <xsl:if test="$mode='login'">Договор № <xsl:value-of select="$contractTitle"/></xsl:if>, Баланс: <xsl:value-of select="$balance"/> руб.
                    <xsl:if test="$mode='pub'"><xsl:value-of select="$pageTitle"/></xsl:if>
            </div>
            <!-- end title  -->

<xsl:value-of select="/data/contract_data/contract/@balance_rest"/>

<xsl:value-of select="/data/contract_data/contract/@status"/>

mysql> explain SELECT (`summa1`-`summa3`)+`summa2` as `balance` FROM `contract_balance` WHERE `mm` = (SELECT MAX(`mm`) FROM `contract_balance` WHERE `yy` = (SELECT MAX(`yy`) FROM `contract_balance`)) AND `cid` = 793;
+----+-------------+------------------+-------+---------------+---------+---------+-------+-------+--------------------------+
| id | select_type | table            | type  | possible_keys | key     | key_len | ref   | rows  | Extra                    |
+----+-------------+------------------+-------+---------------+---------+---------+-------+-------+--------------------------+
|  1 | PRIMARY     | contract_balance | ref   | PRIMARY,cid   | PRIMARY | 4       | const |    69 | Using where              |
|  2 | SUBQUERY    | contract_balance | index | NULL          | cid     | 4       | NULL  | 26545 | Using where; Using index |
|  3 | SUBQUERY    | contract_balance | index | NULL          | cid     | 4       | NULL  | 26545 | Using index              |
+----+-------------+------------------+-------+---------------+---------+---------+-------+-------+--------------------------+
3 rows in set (0.01 sec)

mysql> explain select * from contract_balance where cid=793 order by yy desc, mm desc limit 1;
+----+-------------+------------------+------+---------------+---------+---------+-------+------+-------------+
| id | select_type | table            | type | possible_keys | key     | key_len | ref   | rows | Extra       |
+----+-------------+------------------+------+---------------+---------+---------+-------+------+-------------+
|  1 | SIMPLE      | contract_balance | ref  | PRIMARY,cid   | PRIMARY | 4       | const |   69 | Using where |
+----+-------------+------------------+------+---------------+---------+---------+-------+------+-------------+
1 row in set (0.00 sec)