private String buildUrl(String artistName,String songName){
		
		if(artistName==null) artistName="";
		if(songName==null) songName="";
		
		StringBuilder urlBuilder = new StringBuilder();
		urlBuilder.append(WIKIA_API_URL).append("api.php?func=");
		urlBuilder.append("getSong&artist=").append(artistName);
		urlBuilder.append("&song=").append(songName);
		urlBuilder.append("&fmt=xml");
		
		return urlBuilder.toString();
	}