function resetCalculator(which) {
	document.getElementById(which+'CalculatorBlock').style.display = 'block';
	document.getElementById(which+'EmissionsCalculatorResults').style.display = 'none';
}

function switchFlightTabs(tab) {
	if ( tab == "return" ) {
		document.getElementById('resultsReturn').style.display = 'block';
		document.getElementById('resultsOneWay').style.display = 'none';
		document.getElementById('resultsTabReturn').className = 'emissionsCalculatorResultsTabActive';
		document.getElementById('resultsTabOneWay').className = '';
	}
	else {
		document.getElementById('resultsReturn').style.display = 'none';
		document.getElementById('resultsOneWay').style.display = 'block';
		document.getElementById('resultsTabReturn').className = '';
		document.getElementById('resultsTabOneWay').className = 'emissionsCalculatorResultsTabActive';
	}
}

function calculateFlight() {
	document.getElementById('flightCalculatorBlock').style.display = 'none';
	document.getElementById('flightEmissionsCalculatorResults').style.display = 'block';
	
	distance = document.getElementById('distance').value;
	emissions = Math.round(0.11 * distance);
	trees = calculateTrees(emissions);
	treesPlural = (trees==1)?"":"s";	
	document.getElementById('distanceBlock').innerHTML = distance;
	document.getElementById('emissionsBlock').innerHTML = emissions;
	document.getElementById('treesBlock').innerHTML = trees;
	document.getElementById('treesPluralBlock').innerHTML = treesPlural;	
	document.getElementById('buyNow').href = '/main/onlineshop/?large=' + trees;	
						
	returnDistance = distance * 2;
	returnEmissions = Math.round(0.11 * returnDistance);
	returnTrees = calculateTrees(returnEmissions);
	returnTreesPlural = (returnTrees==1)?"":"s";	
	document.getElementById('returnDistanceBlock').innerHTML = returnDistance;
	document.getElementById('returnEmissionsBlock').innerHTML = returnEmissions;
	document.getElementById('returnTreesBlock').innerHTML = returnTrees;
	document.getElementById('returnTreesPluralBlock').innerHTML = returnTreesPlural;
	document.getElementById('buyNowReturn').href = '/main/onlineshop/?large=' + returnTrees;	
}

function calculateCar() {
	var multipliers={'P':{'S':0.175,'M':0.241,'L':0.331},'D':{'S':0.1699,'M':0.2113,'L':0.3702}};
	var lpgMulti=1.61;
	var distance=document.getElementById('carDistance').value;
	var theForm=document.forms['carCalculator'];
	var fuel=radioGetVal(theForm.fuelType);
	var engine=radioGetVal(theForm.engineSize);
	var multi=(fuel=='L')?lpgMulti:multipliers[fuel][engine];
	var emissions = Math.round(distance*multi);
	
	showEmissionResults('car',distance,emissions);
}

function calculateMotorbike() {
	var multi=0.0816;
	var distance=document.getElementById('motorbikeDistance').value;
	var emissions = Math.round(distance*multi);
	
	showEmissionResults('motorbike',distance,emissions);
}

function showEmissionResults(type,distance,emissions) {
	var trees = calculateTrees(emissions);
	var treesPlural = (trees==1)?"":"s";	
	
	document.getElementById(type+'CalculatorBlock').style.display = 'none';
	document.getElementById(type+'EmissionsCalculatorResults').style.display = 'block';
	
	document.getElementById(type+'DistanceBlock').innerHTML = distance;
	document.getElementById(type+'EmissionsBlock').innerHTML = emissions;
	document.getElementById(type+'TreesBlock').innerHTML = trees;
	document.getElementById(type+'TreesPluralBlock').innerHTML = treesPlural;	
	document.getElementById(type+'BuyNow').href = '/main/onlineshop/?large=' + trees;

}
function toggleFuel(type) {
	var cap=document.getElementById('carCalculatorDistanceCaption');
	var unit=document.getElementById('carDistanceLabel');
	var engine=document.getElementById('carCalculatorSizeBlock');
	cap.innerHTML=(type=='L')?'LPG used:':'Distance travelled:';
	unit.innerHTML=(type=='L')?'L':'km';
	engine.style.display=(type=='L')?'none':'';
}
function radioGetVal(el) {
	for(var i=0;i<el.length;i++) {
		if(el[i].checked) return el[i].value;
	}
	return null;
}
function calculateTrees(kg) {
	var trees=Math.round(kg/600);
	if (kg>0 && trees==0) trees=1;
	return trees;
}