> <onClick><onClick> is what I meant by a tag with a null
> value.

Well, in the XPath data model it's not a tag with a null value, it's an
element with no children. Which gives you the clue how to test for it:

<xsl:if test="onClick[not(child::node())]">

Michael Kay
Software AG
home: Michael.H.Kay@xxxxxxxxxxxx
work: Michael.Kay@xxxxxxxxxxxxxx


 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list