function arrivalNightsUpdate(){
	var startDate = document.getElementById('startDate');
	var endDate = document.getElementById('endDate');
	var sDate = validateDate(startDate.value);
	var eDate = validateDate(endDate.value);
	if(dateExists(sDate) == false){return;}
	if(sDate == "false"){return;}
	var numberNights = document.getElementById('numberNights')
	var dt = sDate.split("-");
	var numnts = parseInt(numberNights.value);
	var myDate = new Date( parseInt(dt[2]), parseInt(dt[1],10)-1,parseInt(dt[0],10)+numnts);
	var day = myDate.getDate()+""; if(day.length == 1){day = "0" + day;}
	var month = (myDate.getMonth()+1+""); if(month.length == 1){month = "0" + month;}
	var year = myDate.getFullYear();
	endDate.value = day + "-" + month + "-" + year;
}

function departureUpdate(){
	var startDate = document.getElementById('startDate');
	var endDate = document.getElementById('endDate');
	var sDate = validateDate(startDate.value);
	var eDate = validateDate(endDate.value);
	if(dateExists(sDate) == false){return;}
	if(dateExists(eDate) == false){return;}
	if(sDate == "false" || eDate == "false"){return;}
	var numberNights = document.getElementById('numberNights')
	var startDay = sDate.substr(0,2);
	var startMonth = sDate.substr(3,2);
	var startYear = sDate.substr(6,4);
	var startStamp = (Date.parse(startMonth+"-"+startDay+"-"+startYear)) / (60 * 60 * 24 * 1000);
	var endDay = eDate.substr(0,2);
	var endMonth = eDate.substr(3,2);
	var endYear = eDate.substr(6,4);
	var endStamp = (Date.parse(endMonth+"-"+endDay+"-"+endYear)) / (60 * 60 * 24 * 1000);
	numberNights.value = endStamp - startStamp;
}

function validateDate(string){
	var validFormat = new RegExp("[0-9]{1,2}[. /-][0-9]{1,2}[. /-]([0-9]{2}$|[0-9]{4}$)");
	var result = validFormat.test(string);
	if(result == false){return "false";}
	string = string.replace(/[/. ]/g,"-");
	var parts = new Array();
	parts = string.split('-');
	if(parts[0].length == 1){parts[0] = "0" + parts[0];}
	if(parts[1].length == 1){parts[1] = "0" + parts[1];}
	if(parts[2].length == 2){parts[2] = "20" + parts[2];}
	string = parts[0] + "-" + parts[1] + "-" + parts[2];
	return string;
}

function dateExists(input) {
 	var dayfield=input.split("-")[0]
  	var monthfield=input.split("-")[1]
   	var yearfield=input.split("-")[2]
	
    returnval=false;
	
	var dayobj = new Date(yearfield, monthfield-1, dayfield)
	if ((dayobj.getMonth()+1!=monthfield)||(dayobj.getDate()!=dayfield)||(dayobj.getFullYear()!=yearfield)){
		var x=1;
	}else{
		returnval=true;
	}
    return returnval;
}