function getPageSize() {
    return screen.width - 21;
}

function resizeContent() {
    var tables = document.getElementsByTagName("table");
    for (var i=0; i < tables.length; i++) {
		var e = tables[i];
		if ((e.className=='full')) {
            e.className = '';
		    e.style.width = getPageSize() + 'px';
		}
	}
}

function init() {
    if (screen.width > 1003) resizeContent();
}

if ('undefined' == typeof String.prototype.trim) {
  String.prototype.trim = function() {
    return this.replace(/^\s+/, '').replace(/\s+$/, '');
  }
}

function numbers_only() {
    if ((event.keyCode < 48 || event.keyCode > 57) && event.keyCode != 13) {
        event.returnValue = false;
        alert("Здесь может быть указано только число!");
    }
}

function validate_day(Day_element) {
    if (!Day_element.value=='' && Day_element.value==0 || Day_element.value>31) {
        alert('Неверно указан день!');
        Day_element.select();
    };
}

function validate_month(Month_element) {
    if (!Month_element.value=='' && Month_element.value==0 || Month_element.value>12) {
        alert('Неверно указан месяц!');
        Month_element.select();
    }
}

function flash(element) {
    element = document.getElementById(element);
    element.className = 'flash_on';
}

function unflash(element) {
    element = document.getElementById(element);
    element.className = 'flash_off';
}

        function CountNigths() {
            var NightsVal = 0;

            var ADay    = parseFloat(document.getElementById('arrival_day').value);
            var AMonth  = parseFloat(document.getElementById('arrival_month').value);
            var AYear   = parseFloat('20' + document.getElementById('arrival_year').value);
            var DDay    = parseFloat(document.getElementById('departure_day').value);
            var DMonth  = parseFloat(document.getElementById('departure_month').value);
            var DYear   = parseFloat('20' + document.getElementById('departure_year').value);

            if  (ADay < 32 & AMonth < 13 & DDay < 32 & DMonth < 13) {
                var ArrDate = new Date(AYear, AMonth - 1, ADay);
                var DepDate = new Date(DYear, DMonth - 1, DDay);
                NightsVal = (((DepDate - ArrDate) / (24 * 60 * 60 * 1000)));
                if (NightsVal.toString().indexOf('.9') > 0) NightsVal = parseInt(NightsVal) + 1;
                document.getElementById('nights').value = parseInt(NightsVal);
            } else document.getElementById('nights').value = '';
            if (parseInt(NightsVal) < 0) document.getElementById('nights').value = ''
        }

init();