DocumentSet docs,
	public Sequence eval(		DocumentSet docs,		Sequence contextSequence,		Item contextItem)		throws XPathException {		if (contextItem != null)			contextSequence = contextItem.toSequence();		String s1 =			getArgument(0)				.eval(docs, contextSequence)				.getStringValue();		String s2 =			getArgument(1)				.eval(docs, contextSequence)				.getStringValue();		if (s1.indexOf(s2) > -1)			return BooleanValue.TRUE;		else			return BooleanValue.FALSE;	}