function carCheckClick(_input, _car_id)
{
	var nr_input = $('car_number[' + _car_id + ']');
	if(!_input.checked)
	{
		nr_input.value = '';
	}
	else if(nr_input.value == '')
	{
		nr_input.value = '1';
	}
	recalculateTotalPrice();
}
function carNumberBlur(_input, _car_id)
{
	if(_input.value == '')
	{
		$('car_checked[' + _car_id + ']').checked = false;
	}
	else
	{
		$('car_checked[' + _car_id + ']').checked = true;
  	if(!_input.value.match(/^[1-9][0-9]*$/))
  	{
  		alert(Phrases.valid_number);
  		_input.focus();
  	}
	}
	recalculateTotalPrice();
}
function recalculateTotalPrice()
{
	var total_price = 0;
	
//                                  	var ids = $$('input[id=^car_id]');
	var ids = $$('input.car_id');
	
	for(var i = 0; i < ids.length; i++)
	{
		var id = ids[i].value;
		var price = parseInt($('car_price[' + id + ']').innerHTML);
		var nr = parseInt($('car_number[' + id + ']').value);
		if((nr != 0) && (!isNaN(nr)))
		{
			total_price += nr*price;
		}
	}
	
	$('total_price').innerHTML = total_price;
	return total_price;
}

function verifyCarSelectionForm()
{
	var ids = $$('input.car_id');
	
	var inputs = 0;
	
	for(var i = 0; i < ids.length; i++)
	{
		var id = ids[i].value;
		var nr_input = $('car_number[' + id + ']');
		if(nr_input.value != '')
	  	{
	  		if(!nr_input.value.match(/^[1-9][0-9]*$/))
	  		{
	  			alert(Phrases.valid_number);
		  		nr_input.focus();
		  		return false;
	  		}
	  		inputs++;
	  	}
	}
	if(inputs == 0)
	{
		alert(Phrases.select_car);
		return false;
	}
	return true;
}