// document has been created, or after the document element has been closed.
if ( _current == null && _document == null )
{
if ( _preRootNodes == null )
_preRootNodes = new Vector();
_preRootNodes.addElement( new ProcessingInstructionImpl( null, target, instruction ) );
}
else
if ( _current == null && _document != null )
_document.appendChild( new ProcessingInstructionImpl( _document, target, instruction ) );
else
_current.appendChild( new ProcessingInstructionImpl( _document, target, instruction ) );
}