How to find out the namespace prefix

Hi,

    I am processing an XML Schema document with XSL. Here is a small snippet :

<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:ewcm="http://w3.ibm.com/standards/xml/released/ewcm"
	targetNamespace="http://w3.ibm.com/standards/xml/released/ewcm"
	elementFormDefault="qualified">
    <xsd:element name="Metadata">
.
.

     What I'd like to do when processing the "<xsd:element
name="Metadata" line is to print out "ewcm:Metadata" . I can figure
out the URI to the namespace for Metadata by looking at the
"targetNamespace" attribute. How can I figure out if a prefix has been
defined for that namespace and if so what it is (in this case, it is
"ewcm")?

Thanks,
Kenneth