var Utils = (function() {
    function validateYear (val) {
        val = $.trim(val)
		var year_re = /^\s*\d{4}\s*$/
		if (!year_re.test(val)) {
			return 'Please enter a valid year. It must be a 4 digits number.'
		}
		return null
    }
    function validateNumber (val) {
        val = $.trim(val)
		var number_re = /^\s*\d*\s*$/
		if (!number_re.test(val)) {
			return 'Price must be a number.'
		}
		return null
    }
    return {
        validateYear  : validateYear,
        validateNumber: validateNumber
    }
})()