function priceDifference() {
    var category = document.getElementsByTagName("SELECT");
    for(var i=0;i<category.length;i++){
		for (j=0; j<category[i].options.length; j++) {
			if (category[i].options[j].innerHTML.indexOf(" $") != -1) {
				//removes any prices
				category[i].options[j].innerHTML = category[i].options[j].innerHTML.substring(0,category[i].options[j].innerHTML.indexOf("$"));
			} 
		}
		for (j=0; j<category[i].options.length; j++) {
			if (category[i].options[j].selected === false) {
				//add price diff
				if (category[i].options[j].value!==';') {
					var priceActual = category[i].options[j].value;
					priceActual = priceActual.substring(0, priceActual.indexOf(";"))
					var actualValue = priceActual;
					
					var priceSelected = category[i].value;
					priceSelected = priceSelected.substring(0, priceSelected.indexOf(";"))
					var selectedValue = priceSelected;
					
					var difference = (actualValue-selectedValue);
					if (difference > 0 ) {
						var operator = ' +';
					} else {
						var operator = ' ';
					}
					var result = difference.toFixed(2);
					category[i].options[j].innerHTML += ' $' + operator + result;
				}
			} 
		}
	}
	
}

function setBG(selName, picId) {
	var a=document.getElementsByName(selName);
	var valueArr=a[0][a[0].selectedIndex].value.split(";");
	document.getElementById(picId).src='./img/configurator/case/' + valueArr[1] + '.jpg';
}

function changeCasePic() {
	setBG('caseBase', 'caseBasePic');
}

function changeSwatchPic() {
	setBG('caseColour', 'colourPic');
	var a=document.getElementsByName('caseColour');
	var c=document.getElementsByName('caseCustom');
	if (c[0].selectedIndex!==0 && a[0].selectedIndex!==0) {
		c[0].selectedIndex=0;
		setBG('caseCustom', 'customPic');
	}
}

function changeCathodePic() {
	setBG('caseLighting', 'cathodePic');
}

function changeStickerPic() {
	setBG('caseSticker', 'stickerPic');

	var a=document.getElementsByName('caseSticker');
	var b=document.getElementsByName('caseTattoo');
	if (a[0].selectedIndex!==0 && b[0].selectedIndex!==0) {
		b[0].selectedIndex=0;
		setBG('caseTattoo', 'tattooPic');
	}
}

function changeTattooPic() {
	setBG('caseTattoo', 'tattooPic');
	var a=document.getElementsByName('caseTattoo');
	var c=document.getElementsByName('caseCustom');
	if (c[0].selectedIndex!==0 && a[0].selectedIndex!==0) {
		c[0].selectedIndex=0;
		setBG('caseCustom', 'customPic');
	}
}

function changeCustomPic() {
	setBG('caseCustom', 'customPic');
	var a=document.getElementsByName('caseTattoo');
	var b=document.getElementsByName('caseColour');
	var c=document.getElementsByName('caseCustom');
	if (c[0].selectedIndex!==0) {		
		if (a[0].selectedIndex!==0) { 
			a[0].selectedIndex=0;
			setBG('caseTattoo', 'tattooPic');
		}
		if (b[0].selectedIndex!==0) { 
			b[0].selectedIndex=0;
			setBG('caseColour', 'colourPic');
		}
	}
}