checkboxes abd FF

have a simple calculator i made with checkboxes and some Js.

the problem is that it does not work in FF.

any idea how this can work for
IE
Safari
AND FF

function getPrice(amount, boxName){
		total = eval() ;
	
		checked = document.getElementById(boxName).checked
			if (checked){
				total =  parseFloat(form1.Total2.value) + parseFloat(amount);

			}else{
				total =  parseFloat(form1.Total2.value) - parseFloat(amount);

			}
			total.toFixed(2);
		form1.Total2.value = total
		document.getElementById("total").innerHTML = "Total $"+total;
	}

Code (markup):

 

yes, by not using references like this:

form1.Total2.value

assign an id to Total2 and then get the value by document.getElementById("Total2").value instead.