这有效：
<xsl:when test="(price >= 10)">
但这没有（测试中的代码没有执行，并且没有呈现以下列 - 对于任何行）：
<xsl:when test="(price <= 9)">
我在这里测试这个 XML 和 XSL： http ://www.w3schools.com/xsl/tryxslt.asp?xmlfile=cdcatalog&xsltfile=cdcatalog_choose
为什么？
完整的 XSL 在这里：
<?xml version="1.0" encoding="ISO-8859-1"?>
<!-- Edited by XMLSpy® -->
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<html>
<body>
<h2>My CD Collection</h2>
<table border="1">
<tr bgcolor="#9acd32">
<th>Title</th>
<th>Artist</th>
<th>Price</th>
</tr>
<xsl:for-each select="catalog/cd">
<tr>
<td><xsl:value-of select="title"/></td>
<xsl:choose>
<xsl:when test="(price < 9)">
<td bgcolor="#00aaff">
<xsl:value-of select="artist"/>
</td>
</xsl:when>
<xsl:otherwise>
<td><xsl:value-of select="artist"/></td>
</xsl:otherwise>
</xsl:choose>
<td><xsl:value-of select="price"/></td>
</tr>
</xsl:for-each>
</table>
</body>
</html>
</xsl:template>
</xsl:stylesheet>
XML源是这样的：
<?xml version="1.0" encoding="ISO-8859-1"?>
<!-- Edited by XMLSpy® -->
<catalog>
<cd>
<title>Empire Burlesque</title>
<artist>Bob Dylan</artist>
<country>USA</country>
<company>Columbia</company>
<price>10.90</price>
<year>1985</year>
</cd>
<cd>
<title>Hide your heart</title>
<artist>Bonnie Tyler</artist>
<country>UK</country>
<company>CBS Records</company>
<price>9.90</price>
<year>1988</year>
</cd>
<cd>
<title>Greatest Hits</title>
<artist>Dolly Parton</artist>
<country>USA</country>
<company>RCA</company>
<price>9.90</price>
<year>1982</year>
</cd>
<cd>
<title>Still got the blues</title>
<artist>Gary Moore</artist>
<country>UK</country>
<company>Virgin records</company>
<price>10.20</price>
<year>1990</year>
</cd>
<cd>
<title>Eros</title>
<artist>Eros Ramazzotti</artist>
<country>EU</country>
<company>BMG</company>
<price>9.90</price>
<year>1997</year>
</cd>
<cd>
<title>One night only</title>
<artist>Bee Gees</artist>
<country>UK</country>
<company>Polydor</company>
<price>10.90</price>
<year>1998</year>
</cd>
<cd>
<title>Sylvias Mother</title>
<artist>Dr.Hook</artist>
<country>UK</country>
<company>CBS</company>
<price>8.10</price>
<year>1973</year>
</cd>
<cd>
<title>Maggie May</title>
<artist>Rod Stewart</artist>
<country>UK</country>
<company>Pickwick</company>
<price>8.50</price>
<year>1990</year>
</cd>
<cd>
<title>Romanza</title>
<artist>Andrea Bocelli</artist>
<country>EU</country>
<company>Polydor</company>
<price>10.80</price>
<year>1996</year>
</cd>
<cd>
<title>When a man loves a woman</title>
<artist>Percy Sledge</artist>
<country>USA</country>
<company>Atlantic</company>
<price>8.70</price>
<year>1987</year>
</cd>
<cd>
<title>Black angel</title>
<artist>Savage Rose</artist>
<country>EU</country>
<company>Mega</company>
<price>10.90</price>
<year>1995</year>
</cd>
<cd>
<title>1999 Grammy Nominees</title>
<artist>Many</artist>
<country>USA</country>
<company>Grammy</company>
<price>10.20</price>
<year>1999</year>
</cd>
<cd>
<title>For the good times</title>
<artist>Kenny Rogers</artist>
<country>UK</country>
<company>Mucik Master</company>
<price>8.70</price>
<year>1995</year>
</cd>
<cd>
<title>Big Willie style</title>
<artist>Will Smith</artist>
<country>USA</country>
<company>Columbia</company>
<price>9.90</price>
<year>1997</year>
</cd>
<cd>
<title>Tupelo Honey</title>
<artist>Van Morrison</artist>
<country>UK</country>
<company>Polydor</company>
<price>8.20</price>
<year>1971</year>
</cd>
<cd>
<title>Soulsville</title>
<artist>Jorn Hoel</artist>
<country>Norway</country>
<company>WEA</company>
<price>7.90</price>
<year>1996</year>
</cd>
<cd>
<title>The very best of</title>
<artist>Cat Stevens</artist>
<country>UK</country>
<company>Island</company>
<price>8.90</price>
<year>1990</year>
</cd>
<cd>
<title>Stop</title>
<artist>Sam Brown</artist>
<country>UK</country>
<company>A and M</company>
<price>8.90</price>
<year>1988</year>
</cd>
<cd>
<title>Bridge of Spies</title>
<artist>T`Pau</artist>
<country>UK</country>
<company>Siren</company>
<price>7.90</price>
<year>1987</year>
</cd>
<cd>
<title>Private Dancer</title>
<artist>Tina Turner</artist>
<country>UK</country>
<company>Capitol</company>
<price>8.90</price>
<year>1983</year>
</cd>
<cd>
<title>Midt om natten</title>
<artist>Kim Larsen</artist>
<country>EU</country>
<company>Medley</company>
<price>7.80</price>
<year>1983</year>
</cd>
<cd>
<title>Pavarotti Gala Concert</title>
<artist>Luciano Pavarotti</artist>
<country>UK</country>
<company>DECCA</company>
<price>9.90</price>
<year>1991</year>
</cd>
<cd>
<title>The dock of the bay</title>
<artist>Otis Redding</artist>
<country>USA</country>
<company>Atlantic</company>
<price>7.90</price>
<year>1987</year>
</cd>
<cd>
<title>Picture book</title>
<artist>Simply Red</artist>
<country>EU</country>
<company>Elektra</company>
<price>7.20</price>
<year>1985</year>
</cd>
<cd>
<title>Red</title>
<artist>The Communards</artist>
<country>UK</country>
<company>London</company>
<price>7.80</price>
<year>1987</year>
</cd>
<cd>
<title>Unchain my heart</title>
<artist>Joe Cocker</artist>
<country>USA</country>
<company>EMI</company>
<price>8.20</price>
<year>1987</year>
</cd>
</catalog>