jQuery(function() {
      jQuery.extend( {
        insertDateFormated: function(day, month, year, date) {
          var formatedValue = null;
          formatedValue = date.getDate();
          jQuery(day).val(formatedValue);
          formatedValue = date.getMonth() + 1;
          jQuery(month).val(formatedValue);
          jQuery(year).val(date.getFullYear());

          formatedValue = null;
        }
      });

      jQuery(document).ready(function() {
        var date = new Date();
        var arrival = date.getTime() + (2 * 24 * 60 * 60 * 1000);
        var departure = arrival + (7 * 24 * 60 * 60 * 1000);
        date.setTime(arrival);
        jQuery.insertDateFormated('#day_arrival','#month_arrival','#year_arrival',date);
        date.setTime(departure);
        jQuery.insertDateFormated('#day_departure','#month_departure','#year_departure',date);
      });


      jQuery('#calendar_arrival').datepicker({

		showOn: 'button',
        buttonImage: 'http://www.ruegen-katalog.de/layout/calendar.gif',
        buttonImageOnly: true,
        buttonText: 'Kalender',
        dateFormat: 'yy/m/d',
        firstDay: 1,
        minDate: new Date(),
        dayNamesMin: ['So', 'Mo', 'Di', 'Mi', 'Do', 'Fr', 'Sa'],
        monthNames: ['Januar','Februar','März','April','Mai','Juni','Juli','August','September','Oktober','November','Dezember'],
        nextText: 'vor',
        prevText: 'zurück',

        beforeShow: function(input, inst) {
          var day = parseInt(jQuery('#day_arrival').val());
          var month = parseInt(jQuery('#month_arrival').val());
          var year = parseInt(jQuery('#year_arrival').val());

          if(!isNaN(day) && !isNaN(month) && !isNaN(year) && day>=1 && day<=31 && month>=1 && month<=12 && year>2000) {
            var date = new Date(year, month-1, day);
            jQuery('#calendar_arrival').datepicker('option', 'defaultDate', date);
            jQuery('#calendar_arrival').datepicker('setDate', date);
            date = null;
          }

          day = month = year = null;
        },

        onSelect: function(dateText, inst) {
          var arrDate = dateText.split('/');
          var date = new Date(arrDate[0], arrDate[1]-1, arrDate[2], 12, 0, 0);
          arrDate = null;
          jQuery.insertDateFormated('#day_arrival','#month_arrival','#year_arrival',date);

          // test and set date
          var earliest_departure = date.getTime() + (24 * 60 * 60 * 1000);
          date.setTime(earliest_departure);
          earliest_departure = null;

          var day = parseInt(jQuery('#day_departure').val());
          var month = parseInt(jQuery('#month_departure').val());
          var year = parseInt(jQuery('#year_departure').val());

          if(!isNaN(day) && !isNaN(month) && !isNaN(year) && day>=1 && day<=31 && month>=1 && month<=12 && year>2000) {
            var date_departure = new Date(year, month-1, day);
            if(date_departure.getTime() < date.getTime()) {
              jQuery.insertDateFormated('#day_departure','#month_departure','#year_departure',date);
            }
            date_departure = null;
          } else {
            jQuery.insertDateFormated('#day_departure','#month_departure','#year_departure',date);
          }

          date = day = month = year = null;
        }
      });

     
      
      jQuery('#calendar_departure').datepicker({
        showOn: 'button',
        buttonImage: 'http://www.ruegen-katalog.de/layout/calendar.gif',
        buttonImageOnly: true,
        buttonText: 'Kalender',
        dateFormat: 'yy/m/d',
        firstDay: 1,
        minDate: new Date(),
        dayNamesMin: ['So', 'Mo', 'Di', 'Mi', 'Do', 'Fr', 'Sa'],
        monthNames: ['Januar','Februar','März','April','Mai','Juni','Juli','August','September','Oktober','November','Dezember'],
        nextText: 'vor',
        prevText: 'zurück',

        beforeShow: function(input, inst) {
          // set minDate 
          var day = parseInt(jQuery('#day_arrival').val());
          var month = parseInt(jQuery('#month_arrival').val());
          var year = parseInt(jQuery('#year_arrival').val());

          if(!isNaN(day) && !isNaN(month) && !isNaN(year) && day>=1 && day<=31 && month>=1 && month<=12 && year>2000) {
            var date = new Date(year, month-1, day);
            date.setTime(date.getTime() + (24 * 60 * 60 * 1000));
            jQuery('#calendar_departure').datepicker('option', 'minDate', date);
            date = null;
          }

          var day = parseInt(jQuery('#day_departure').val());
          var month = parseInt(jQuery('#month_departure').val());
          var year = parseInt(jQuery('#year_departure').val());

          if(!isNaN(day) && !isNaN(month) && !isNaN(year) && day>=1 && day<=31 && month>=1 && month<=12 && year>2000) {
            var date = new Date(year, month-1, day);
            jQuery('#calendar_departure').datepicker('option', 'defaultDate', date);
            jQuery('#calendar_departure').datepicker('setDate', date);
            date = null;
          }

          day = month = year = null;
        },

        onSelect: function(dateText, inst) {
          var arrDate = dateText.split('/');
          var date = new Date(arrDate[0], arrDate[1]-1, arrDate[2], 12, 0, 0);
          arrDate = null;
          jQuery.insertDateFormated('#day_departure','#month_departure','#year_departure',date);
          date = null;
        }
      });
    });