code: public String getFrameDataString(String id)
  	{
  		if (allow(ID3V2))
  		{
  			return id3v2.getFrameDataString(id);
  		}
  		return null;
  	}
docs: Returns the textual information contained in the frame specifed by the
  id.  If the frame does not contain any textual information or does not
  exist, then the empty string is returned (id3v2 only).  The id should
  be one of the static strings defined in the ID3v2Frames class.
  
  @param id the id of the frame to get data from
  @return the textual information of the frame
  @exception ID3v2FormatException if the data of the frame is incorrect