// JavaScript Document
<!--
function calculate_total(){
	var ttl = 0;
	var len = document.forms['calc']['length'].value;
	var wid = document.forms['calc']['width'].value;
	var subs = document.forms['calc']['substrate'].value;

   if (len.length == 0)
   {
      return;
   }

   if (wid.width == 0)
   {
      return;
   }

   if (subs.substrate == 0)
   {
      return;
   }

ttl = len * wid;


switch (subs){
	case "A":
	ttl *= 0.10;
	break;
	case "B":
	ttl *= 0.16;
	break;
	case "C":
	ttl *= 0.34;
	break
	case "D":
	ttl *= 0.38;
	break
	case "E":
	ttl *= 0.42;
	break;
    case "F":
	ttl *= 0.50;
	break;
	case "G":
	ttl *= 0.70;
	break;
}

   var price = ttl.toFixed(2);
   document.getElementById('total').value=price;

 } // end function definition

//-->