text: public static bool? ToBooleanOrNull(string stringValue){if (stringValue == null){return null;}if (EqualsIgnoreCase("yes", stringValue) || EqualsIgnoreCase("true", stringValue)|| EqualsIgnoreCase("1", stringValue) || EqualsIgnoreCase("on", stringValue)){return true;}else{if (EqualsIgnoreCase("no", stringValue) || EqualsIgnoreCase("false", stringValue)|| EqualsIgnoreCase("0", stringValue) || EqualsIgnoreCase("off", stringValue)){return false;}else{return null;}}}