function roundNumber(num, dec) 
{
	var result = Math.round(num*Math.pow(10,dec))/Math.pow(10,dec);
	return result;
}
function selectQuantity()
{
	var quantity = document.getElementById('prodQuantity');
	var myindex = quantity.selectedIndex;
    var sel_index = quantity.options[myindex].id;
	var price = document.getElementById('price').value;
	new_price = sel_index * price;
	newprice = roundNumber(new_price,2);
	document.getElementById('totalPrice').innerHTML = "$" + newprice;
}

function changeSize()
{	
	var prodSize = document.getElementById('prodSize');
	var myindex = prodSize.selectedIndex;
    var sel_price = prodSize.options[myindex].title;
	//document.getElementById('prodQuantity').value = 1;
	var quantity = document.getElementById('prodQuantity');
	quantity.selectedIndex = 0;
	document.getElementById('price').value = sel_price;
	document.getElementById('totalPrice').innerHTML = "$" + sel_price;	
}

function formsubmit()
{
	var quantity = document.getElementById('prodQuantity');
	var myindex = quantity.selectedIndex;
    var sel_qty = quantity.options[myindex].value;
	document.getElementById('qty').value = sel_qty;

	var size_name = document.getElementById('prodSize');
	myindex = size_name.selectedIndex;
    sel_qty = size_name.options[myindex].value;
	document.getElementById('size_name').value = sel_qty;

	document.getElementById('total').value = document.getElementById('totalPrice').innerHTML;
}