Bug 193875 we can not get an entir url by IHTMLActionHandler
we can not get an entir url by IHTMLActionHandler, so word emitter dose not write the right url. now hyperlink drill through in word emitter doesn't work.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/ParameterAccessor.java
return ""; 
		String sessionId = request.getSession( ).getId( );
		String fileSeparator = "\\"; 
		if ( filePath.lastIndexOf( fileSeparator ) == -1 )
			fileSeparator = "/"; 
		
		if ( filePath.lastIndexOf( fileSeparator ) != -1 )
		{
			documentName = filePath.substring( filePath
					.lastIndexOf( fileSeparator ) + 1 );
		}
		else
		{
			documentName = filePath;
		}
		String hashCode = Integer.toHexString( filePath.hashCode( ) );
		return documentFolder + File.separator + sessionId + File.separator
				+ hashCode + File.separator + documentName;
	}
	/**
	 * Clears the report document/image files which had been created last time
	 * the server starts up.
	 */
	protected static void clearTempFiles( )
	{
		
		File file = new File( documentFolder );
		deleteDir( file );
		makeDir( documentFolder );