function validateMaskFormatSymbol(sNewSymbol) {
		if (/^.$/i.test(sNewSymbol)) {
			return true;
		}
		Log.error("The mask format symbol '" + sNewSymbol + "' is not valid");
		return false;
	}
Checks if the specified symbol is valid.
@param {string} sNewSymbol Symbol to be validated
@returns {boolean} True if the specified symbol is valid, false otherwise
@private