// just a comment...

var milliseconds_per_day = 24*60*60*1000;

function clear()
{
  elem = document.getElementById('namn');
  if(elem.value == 'Företagsnamn om faktura annars namn')
    {
      elem.value = '';
    }
}

function change_weekday(elem)
{
  if(elem.value == 'Söndag' || elem.value == 'Måndag')
    elem.style.color = "grey";
  else
    elem.style.color = "black";
  update_date(elem.selectedIndex);
}


function change_date()
{
  var eDate = document.getElementById('datum');  
  var eMonth = document.getElementById('manad');
  
  var date = eDate.value;
  var month = eMonth.value;

  var currentDate = new Date();
  var year = currentDate.getFullYear();

  var selectedDate = new Date(year, month, date);

  var eWeekday = document.getElementById('dag');
  eWeekday.selectedIndex = selectedDate.getDay();
  change_weekday(eWeekday);
  eVarning = document.getElementById('varning');
  if(selectedDate.getDay() < 2)
  {
    eVarning.innerHTML = 'Observera att vi inte har öppet måndagar och söndagar.';
    eVarning.style.display = 'block';
  }
  else
  {
    eVarning.style.display = 'none';
  }
}

function update_date(weekday)
{
  //calculate current selected date
  var eDate = document.getElementById('datum');  
  var eMonth = document.getElementById('manad');
  
  var date = eDate.value;
  var month = eMonth.value;
  
  var currentDate = new Date();
  var year = currentDate.getFullYear();
      
  var selectedDate = new Date(year, month, date);

  var date_day = selectedDate.getDay();

  if(date_day != weekday)
  {
    var diff = (date_day - weekday) * milliseconds_per_day;

    selectedDate.setTime(selectedDate.getTime() - diff);
    
    eDate.selectedIndex = selectedDate.getDate()-1;
    eMonth.selectedIndex = selectedDate.getMonth();
  }
}

function validate_form()
{
  var eTelefon = document.getElementById('telefon');
  var form = document.getElementById('book_form');
  var eWeekday = document.getElementById('dag');

  if(eTelefon.value == '')
    {
      alert('Telefonnummer krävs för bokning');
    }
  else if(eWeekday.selectedIndex  < 2)
    {
      alert('Vi har tyvärr stängt Söndagar och Måndagar');
    }
  else
    {
      //check that date and weekday matches
      var eDate = document.getElementById('datum');  
      var eMonth = document.getElementById('manad');
  
      var date = eDate.value;
      var month = eMonth.value;

      var currentDate = new Date();
      var year = currentDate.getFullYear();

      var selectedDate = new Date(year, month, date);

      var date_day = selectedDate.getDay();

      if( date_day != eWeekday.selectedIndex )
      {
	alert('Datumet överensstämmer inte med dagen');
      }
      else
      {
	form.submit();
      }
    }
}