XSL Sum of nodes - xslt

Question

I am trying to calculate the SUM of some nodes. A Learner will have 1 or more Learning Aims, and I need to know the total of the GLH node for the Learning Aims for the learner.
Here is some sample XML.
<Learner>
<LearnRefNumber>422</LearnRefNumber>
<FamilyName>John</FamilyName>
<GivenNames>Smith</GivenNames>
<LearningDelivery>
<LearnAimRef>zilsk14a</LearnAimRef>
<AimType>4</AimType>
<AimSeqNumber>1</AimSeqNumber>
<GLH>2775</GLH>
</LearningDelivery>
<LearningDelivery>
<LearnAimRef>zilsk14b</LearnAimRef>
<AimType>4</AimType>
<AimSeqNumber>2</AimSeqNumber>
<GLH>2500</GLH>
</LearningDelivery>
</Learner>
Here is my XSL. The count of the Learning Aims works fine, but I am struggling to SUM up the GLH.
<xsl:for-each select="t:Learner">
<div class="learner">
<xsl:variable name="LearningAims" select="count(t:LearningDelivery)" />
<xsl:variable name="LearnerGLH" select="sum(t:LearningDelivery/GLH)" />
<table>
<tr>
<th>Learner Ref</th>
<th>Learning Aims</th>
<th>Total GLH</th>
</tr>
<tr>
<td>
<xsl:value-of select="t:LearnRefNumber" />
</td>
<td>
<xsl:value-of select="$LearningAims" />
</td>
<td>
<xsl:value-of select="$LearnerGLH" />
</td>
</tr>
</table>
</div>
Please help. Many thanks

Answer 1

You're writing sum(t:LearningDelivery/GLH), but in the input XML the LearningDelivery and GLH elements are in the same namespace. You want sum(t:LearningDelivery/t:GLH).