Probleme insertion Image file XSL

In my file xsl
I try to insert an image that will Display High in a PDF generate

I tried several suitcases, but I receive always errors

Here my code :

<xsl:attribute name="src">
    <xsl:value-of select="logoCommisonScolaire.gif"/>


Errors obtained:

2013-01-11 17:53:06 [ERROR] TC50ReportController 0 Fonction ‘generatePdf’ Ligne ‘1579’ Erreur lors de la transformation du XSL-FO en PDF : [INFO] Using org.apache.xerces.parsers.SAXParser as SAX2 Parser
[INFO] FOP 0.20.5
[INFO] Using org.apache.xerces.parsers.SAXParser as SAX2 Parser
[INFO] building formatting object tree
[INFO] setting up fonts
[ERROR] Unsupported element encountered: img (Namespace: default). Source context: file:/tmp/ (line: 2, col: 1223)
[ERROR] Expected XSL-FO (root, page-sequence, etc.), SVG (svg, rect, etc.) or elements from another supported language.
[INFO] [1]
[ERROR] no handler defined for img foreign xml
[INFO] Parsing of document complete, stopping renderer