And operator usage in XSL

Hi,

 I am following criteria in my XSL:Fo, for classifying
the page layout... 


<xsl:when test="((substring-before($WidthTmp,'pt')
&lt;= 845.0) and (substring-before($HeightTmp,'pt')
&gt; 598.0)) and substring-before($WidthTmp,'pt') &lt;
substring-before($HeightTmp,'pt') ">
                <xsl:call-template
name="Page_Layout_SetupA4Portrait_FitToFrame" />
</xsl:when> 
                        
<xsl:when test="(substring-before($WidthTmp,'pt')
&gt;= 598.0) and (substring-before($HeightTmp,'pt')
&lt;= 845.0) and (substring-before($HeightTmp,'pt')
&lt; substring-before($WidthTmp,'pt'))">
        <xsl:call-template
name="Page_Layout_SetupA4Landscape_FitToFrame"/>
</xsl:when> 


Here I am using "and" operator.. Is it correct?
my inputs are width="838.8pt" height="607.68pt"

While running this code to generate a pdf, I getting 
the following error msg..
Exceptionfile:///C:/Attachment.fo:15:2125 No
meaningful layout in
block after many attempts.  Infinite loop is assumed. 
Processing halted.

Can you identify where is the problem?
thanks in advance.
Regards,
Arul


        
                
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