code: public static String getValueFromUrl(String url, String preText, int length) {
  		String urlContents = getUrlContents(url);
  		int indexOf = urlContents.indexOf(preText);
  		if (indexOf != -1) {
  			indexOf += preText.length();
  			String substring = urlContents.substring(indexOf, indexOf + length);
  			return substring;
  		}
  		return null;
  	}
docs: Gets the value from url based on pre-text value from the response.
  
  @param url     the url
  @param preText the pre text
  @param length  the length
  @return the value from url