private int handleString(LexicalAnalyser analyser, int beginIndex)
			throws AnalyseException {
		String content = analyser.getSentence();
		for (int index = beginIndex + 1; index < content.length(); index++) {
			char c = content.charAt(index);
			if (c == '\'') {
				int endIndex = index;
				if (index != content.length() - 1) {
					char nextC = content.charAt(index + 1);
					if (!WordTable.isDelimiter(nextC)
							&& !WordTable.isOverableLetter(nextC)
					/* && !WordTable.isDelimiterPart(nextC) */) {
						throw new AnalyseException(String.format(
								"Error: Undefined word [%s]",
								content.substring(beginIndex, endIndex + 2)));
					}
				}
				return this.addResultToAnalyserAndGetResult(analyser,
						beginIndex + 1, endIndex) + 1;
			}
		}
		throw new AnalyseException(String.format("Error: [%s] is not a string",
				content.substring(beginIndex)));
	}