Image @ 100% width for HTML output

Hi,
I’m actually trying to modify an HTML conversion stylesheet to automatically display all <imagedata> contained into a <mediaobject> at 100% of the available width in the HTML page or the table cell…
I tried to play somehow with these lines in the XSL file but I’m struggling with the syntaxe to provide a correct output…

<xsl:template match="d:imagedata" mode="construct">
….
….
</xsl:template>

Of course, I’m trying to achieve that without having to use the width attribute on the imagedata object because the source XML is also used for a PDF publication, and I’d like to keep the true width in that case…

Many thanks in advance for your answers,
Regards,
Jeff