var form=document.getElementById('hotels_form');
  var today=new Date();
  var tommorow=new Date();
  var dayAmounts=1;
  today.setTime(today.getTime());
  tommorow.setTime(tommorow.getTime()+86400000);
  var year=today.getYear();
  var month=today.getMonth();
  var day=today.getDate();
  month++;
  
  function fieldGetDate(dane)
  {
  	var d=new Date();
	d.setDate(dane.day);
	d.setMonth(dane.month-1);
	d.setFullYear(dane.year);
	return d;
  }
  
  function setFormDate(dane)
  {
  	day=dane.date.getDate();
	month=dane.date.getMonth()+1;
  	dane.day.value=(day<10?'0':'')+day;
	dane.month.value=(month<10?'0':'')+month;
	dane.year.value=dane.date.getFullYear();
  }
  
  form.ar_month.onchange=
  form.ar_year.onchange=
  form.ar_day.onchange=function()
  {
  	dat=fieldGetDate({day:form.ar_day.value,month:form.ar_month.value,year:form.ar_year.value});
	dat.setTime(dat.getTime()+(dayAmounts*24*3600*1000));
	setFormDate({
		date:dat,
		day:form.dep_day,
		month:form.dep_month,
		year:form.dep_year
	});
  }
  
  form.dep_day.onchange=
  form.dep_month.onchange=
  form.dep_year.onchange=function()
  {
  	dat1=fieldGetDate({day:form.ar_day.value,month:form.ar_month.value,year:form.ar_year.value});
  	dat2=fieldGetDate({day:form.dep_day.value,month:form.dep_month.value,year:form.dep_year.value});
	if(dat2.getTime()<dat1.getTime())
	{
		alert('Data wyjazdu nie może być mniejsza od daty przyjazdu.');
		return false;
	}
	dat=new Date();
	dat.setTime(dat2.getTime()-dat1.getTime());
	dayAmounts=Math.round(dat.getTime()/(24*3600*1000));
  }
  
  for (var i=0;i<form.ar_year.length;i++)
  {
  	if(form.ar_year.options[i].value==year)
	{
		form.ar_year.options[i].selected=true;
		break;
	}
  }
  for (var i=0;i<form.dep_year.length;i++)
  {
  	if(form.dep_year.options[i].value==tommorow.getYear())
	{
		form.dep_year.options[i].selected=true;
		break;
	}
  }
  
  for (i=0;i<form.ar_month.length;i++)
  {
  	if(form.ar_month.options[i].value==month)
	{
		form.ar_month.options[i].selected=true;
		break;
	}
  }
   for (i=0;i<form.dep_month.length;i++)
  {
  	if(form.dep_month.options[i].value==tommorow.getMonth()+1)
	{
		form.dep_month.options[i].selected=true;
		break;
	}
  }
  
  for (i=0;i<form.ar_day.length;i++)
  {
  	if(form.ar_day.options[i].value==day)
	{
		form.ar_day.options[i].selected=true;
		break;
	}
  }
  for (i=0;i<form.dep_day.length;i++)
  {
  	if(form.dep_day.options[i].value==tommorow.getDate())
	{
		form.dep_day.options[i].selected=true;
		break;
	}
  }

function ZmienDni(day,month,year){
	var si=day.selectedIndex;
	day.options.length = 0;
	var s=month.value;

	if (s==2){
		rok=year.value;
		rok=rok-2000;
		if (Math.floor(rok/4)==rok/4) Dlugosc=29;
		else Dlugosc=28;
		day.options.length=Dlugosc;
		for (i=0 ; i<Dlugosc ; i++){
		    if (i<9){
			z=i+1;
			day.options[i].text=z;
			day.options[i].value='0'+z;
		    }else{
			day.options[i].text=i+1;
			day.options[i].value=i+1;
		    }
		}
	}else
	if (s==1 || s==3 || s==5 || s==7 || s==8 || s==10 || s==12){
		day.options.length=31;
		for (i=0 ; i<31 ; i++){
		    if (i<9){
			z=i+1;
			day.options[i].text=z;
			day.options[i].value='0'+z;
		    }else{
			day.options[i].text=i+1;
			day.options[i].value=i+1;
		    }
		}
	}
	else {
		day.options.length=30;
		for (i=0 ; i<30 ; i++){
		    if (i<9){	
			z=i+1;
			day.options[i].text=z;
			day.options[i].value='0'+z;
		    }else{
			day.options[i].text=i+1;
			day.options[i].value=i+1;
		    }
		}
	}
	
	if (si>=day.options.length)
		si=0;
	day.selectedIndex=si;
}