function updateTotal(){
	var inpts = document.getElementsByTagName("INPUT");
	var amt = 7;
	
	for(var i=0; i<inpts.length; i++){
		if(inpts[i].type == "radio"){
			if(inpts[i].checked){
				switch(inpts[i].id){
					case "rad2":
						amt =  parseFloat(mediumamt);
						break;
					case "rad3":
						amt =  parseFloat(largeamt);
						break;
					default:
						amt = parseFloat(smallamt);
				}
			}
		}
	}
	
	var qty = parseInt(document.getElementById("quantity").value);
	var shipping = parseFloat(document.getElementById("shipping").value);
	
	var subtotal = amt*qty
	var total = (amt*qty) + shipping;
	subtotal = Math.round(subtotal*100)/100 
	total = Math.round(total*100)/100 
		
	document.getElementById("showSubTotal").innerHTML = "$"+subtotal;
	document.getElementById("showShipping").innerHTML = "$"+shipping;
	document.getElementById("showTotal").innerHTML = "$"+total;
	document.getElementById("amount").value = amt;
	
}

function selSize(num){
	if(document.getElementById){
		var r1 = document.getElementById("rad1");
		var r2 = document.getElementById("rad2");
		var r3 = document.getElementById("rad3");
		
		r1.checked = (num==46)?true:false;
		r2.checked = (num==57)?true:false;
		r3.checked = (num==810)?true:false;
		
		updateTotal();
	}
}