Well the VCTMovementInstruction and its child DocPurpose are in the namespace
http://schemas.microsoft.com/dynamic...entInstruction so you need to bind a prefix to that namespace URI and use the prefix to qualify the element names:
Code:
<xsl:stylesheet
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0"
xmlns:mi="http://schemas.microsoft.com/dynamics/2006/02/documents/VCTMovementInstruction">
<xsl:template match="/">
<xsl:value-of select="Envelope/Body/mi:VCTMovementInstruction/mi:DocPurpose"/>
</xsl:template>
</xsl:stylesheet>
Note that the forum software seems to shorten URIs so make sure you use the full URI
http://schemas.microsoft.com/dynamic...entInstruction